WarlockAlan

Summary

Chapter 7 is Consumers, Producers, and the Efficiency of Markets. This chapter explains consumer surplus, producer surplus and the total surplus in the market.

Consumer surplus

• the amount a buyer is willing to pay for a good minus the amount the buyer actually pays for it

Producer surplus

• the amount a seller is paid for a good minus the seller’s cost of providing it

Total surplus= consumer surplus + producer surplus= (value to byers- amount paid by buyers)+ (amount received by sellers- cost to sellers)

• amount paid by buyers= amount received by sellers- cost to sellers

• Total surplus= value to buyers- cost to sellers

Efficiency of Market

• Free markets allocate the supply of goods to the buyers who value them most, as measured by their willingness to pay.
• Free markets allocate the demand for goods to the sellers who can produce then at the lowest cost.
• Free markets produce the quantity of goods that maximizes the sum of consumer and producer surplus.

Definitions

1. Welfare economics– the study of how the allocation of resources affects economic well-being

2. Willingness to pay– the maximum amount that a buyer will pay for a good

3. Consumer surplus– the amount a buyer is willing to pay for a good minus the amount the buyer actually pays for it

4. Cost– the value of everything a seller must give up to produce a good

5. Producer surplus– the amount a seller is paid for a good minus the seller’s cost of providing it

6. Efficiency– the property of a resource allocation of maximizing the total surplus received by all members of society

7. Equality– the property of distributing economic prosperity uniformly among the members of society

Review

I did all questions correctly! Excellent!

Summary

Chapter 6 is Supply, Demand, and Government Policies. This chapter explains maximum price, minimum price and how sellers/consumers burden the tax.

Maximum price

• Also called price ceiling– a legal maximum on the price at which a good can be sold

• If the maximum price is lower than the equilibrium price, we call it a price ceiling that is binding(because this price ceiling will affect the equilibrium price).

• The quantity demanded will increase and quantity supplied will decrease so there is shortage(excess demand).

Minimum price

• Also called price floor– a legal minimum on the price at which a good can be sold

• If the minimum price is higher than the equilibrium price, we call it a price floor that is binding(because this price floor will affect the equilibrium price).

• The quantity demanded will decrease and quantity supplied will increases so there is surplus(excess supply).

• For elastic supply and inelastic demand, buyers burden more tax than sellers.

• For inelastic supply and elastic demand, sellers burden more tax than sellers.

Conclusion: A tax burden falls more heavily on the side of the market that is less elastic.

Definitions

1. Price ceiling– a legal maximum on the price at which a good can be sold

2. Price floor– a legal minimum on the price at which a good can be sold

3. Tax incidence– the manner in which the burden of a tax is shared among participants in a market

Review

There are some exercises in this book. I recorded questions I didn’t answer correctly here.

1. When the government imposes a binding price floor, it causes_____ (Correct answer: D)

a. the supply curve to shift to the left

b. the demand curve to shift to the right

c. a shortage of the good to develop

d. a surplus of the good to develop

My wrong answer: C

2. Which of the following increases quantity supplied, decreases quantity demanded, and increases the price that consumer pay? (Correct answer: C)

a. the passage of a tax on a good

b. the repeal of a tax on a good

c. the imposition of a binding price floor

d. the removal of a binding price floor

My wrong answer: D

Summary

Chapter 5 is Elasticity and its Application. This chapter introduces elasticity(a measure of the responsiveness of quantity demanded or quantity supplied to a change in one of its determinants).

Price elasticity of demand

• measure of how much the quantity demanded of a good responds to a change in the price of that good

• Price elasticity of demand =

• Always a negative number. (As price increases, the quantity demanded decreases.)

• absolute value >1 elastic (change in unit quantity demanded is greater the change in unit price)

• absolute value<1 inelastic(change in unit quantity demanded is smaller the change in unit price)

Income elasticity of demand

• a measure of how much the quantity demanded of a good responds to a change in consumers’ income

• Income elasticity of demand=

• Always smaller than 1. Because not all income is used for buying this good.

• If the value is positive, this good is a kind of normal good. (As income increases, the demand for normal goods increases.)

• If the value is negative, this good is a kind of inferior good.(As income decreases, the demand for inferior goods decreases.)

Cross-price elasticity of demand

• a measure of how much the quantity demanded of one good responds to a change in the price of another good

• Cross-price elasticity of demand=

• If the value is positive, good A and good B are substitutes.(As price of good B increases, the demand for B decreases and the demand for its substitutes good A increases.)

• If the value is negative, good A and good B are complements.(As price of good B increases, the demand for B decreases and the demand for its complements good A decreases.)

Price elasticity of supply

• a measure of how much the quantity supplied of a good responds to a change in the price of that good

• Price elasticity of supply=

• Always a positive number. (As price increases, the quantity supplied increases.)

• absolute value>1 elastic (change in unit quantity demanded is greater the change in unit price)

• absolute value<1 inelastic (change in unit quantity demanded is smaller the change in unit price)

Applications

• Total revenue= price * quantity

• For elastic demand, the lower the price, the greater the revenue. (5080 < 65110)

• For inelastic demand, the lower the price, the lower the revenue.（1480 > 1088 ）

Definitions

1. Elasticity– a measure of the responsiveness of quantity demanded or quantity supplied to a change in one of its determinants

2. Price elasticity of demand– a measure of how much the quantity demanded of a good responds to a change in the price of that good, computed as the percentage change in quantity demanded divided by the percentage change in price

3. Total revenue– the amount paid by buyers and received by sellers of a good, computed as the price of the good times the quantity sold

4. Income elasticity of demand– a measure of how much the quantity demanded of a good responds to a change in consumers’ income, computed as the percentage change in quantity demanded divided by the percentage change in income

5. Cross-price elasticity of demand– a measure of how much the quantity demanded of one good responds to a change in the price of another good, computed as the percentage change in quantity demanded of the first good divided by the percentage change in price of the second good

6. Price elasticity of supply– a measure of how much the quantity supplied of a good responds to a change in the price of that good, computed as the percentage change in quantity supplied divided by the percentage change in price

Review

There are some exercises in this book. I recorded questions I didn’t answer correctly here.

1.In competitive markets, farmers adopt new technologies that will eventually reduce their revenue because_____ (Correct answer: A)

a. each farmer is a price taker

b. farmers are short-sighted

c. regulation requires the use of best practices

d. consumers pressure farmers to lower prices

My wrong answer: D

Summary

Chapter 4 is The Market Forces of Supply And Demand. This chapter explains how market force(supply/demand) determines the allocation of resources（the quantity and price of goods in the market.

Supply/Demand Curve

Quantity demand

• The demand curve slopes downward.
• Other things being equal, the quantity demanded of a good falls when the price of the good rises. (The law of demand)

• When the demand increases, we can say there is an extension along the demand curve. When the demand decreases, we can say there is a contraction along the demand curve.

• You can use a demand schedule to show the relationship between the price of a good and the quantity demanded.

Quantity supply

• The supply curve slopes upward.
• Other things being equal, the quantity supplied of a good rises when the price of the good rises. (The law of supply)

• When the supply increases, we can say there is an extension along the supply curve. When the demand decreases, we can say there is a contraction along the supply curve.

• You can use a supply schedule to show the relationship between the price of a good and the quantity supplied.

Shifts in the demand curve

• The demand curve shifts as the demand changes due to any reasons except the change of the price. In other words, the demand changes at any given price.

• The demand increases when the demand curve shifts to the right, the demand decreases when the demand curve shifts to the left.

• Many reasons lead to the shift in the demand curve. e.g Income, Price of related goods, Tastes, Expectations of future price, Number of byers.

Shifts in the supply curve

• The supply curve shifts as the supply changes due to any reasons except the change of the price. In other words, the supply changes at any given price.

• The supply increases when the supply curve shifts to the right, the supply decreases when the supply curve shifts to the left.

• Many reasons lead to the shift in the supply curve. e.g Technology of production, Expectations of future price, Number of sellers.

Supply and Demand Together

Excess supply/demand

• When the price above the equilibrium price（the price when supply curve and demand curve intersect), the quantity supplied is greater than the quantity demanded. In other words, there is a excess supply(surplus).

• When the price below the equilibrium price（the price when supply curve and demand curve intersect), the quantity supplied is smaller than the quantity demanded. In other words, there is a excess demand(shortage).

• As a result, the market price moves towards the equilibrium price.

How to influence equilibrium price and equilibrium quantity

• When the supply curve shifts to the right, the equilibrium price decreases and the equilibrium quantity increases.

You can also use the diagrams to analyze the change of equilibrium price and equilibrium quantity when the demand curve shifts or the supply curve shifts to the left.

Definitions

1. Market– a group of buyers and sellers of a particular good or service

2. Competitive market– a market in which there are many buyers and many sellers so that each has a negligible impact on the market price

3. Quantity demanded– the amount of a good that buyers are willing and able to purchase

4. Law of demand– the claim that, other things being equal, the quantity demanded of a good falls when the price of the good rises

5. Demand schedule– a table that shows the relationship between the price of a good and the quantity demanded

6. Demand curve– a graph of the relationship between the price of a good and the quantity demanded

7. Normal good– a good for which, other things being equal, an increase in income leads to an increase in demand

8. Inferior good– a good for which, other things being equal, an increase in income leads to a decrease in demand

9. Substitutes– two goods for which an increase in the price of one leads to an increase in the demand for the other

10. Complements– two goods for which an increase in the price of one leads to a decrease in the demand for the other

11. Quantity supplied– the amount of a good that sellers are willing and able to sell

12. Law of supply– the claim that, other things being equal, the quantity supplied of a good rises when the price of the good rises

13. Supply schedule– a table that shows the relationship between the price of a good and the quantity supplied

14. Supply curve– a graph of the relationship between the price of a good and the quantity supplied

15. Equilibrium– a situation in which the market price has reached the level at which quantity supplied equals quantity demanded

16. Equilibrium price– the price that balances quantity supplied and quantity demanded

17. Equilibrium quantity– the quantity supplied and the quantity demanded at the equilibrium price

18. Surplus– a situation in which quantity supplied is greater than quantity demanded

19. Shortage– a situation in which quantity demanded is greater than quantity supplied

20. Law of supply and demand– the claim that the price of any good adjusts to bring the quantity supplied and the quantity demanded of that good into balance

Review

There are some exercises in this book. I recorded questions I didn’t answer correctly here.

1. If the economy goes into a recession and incomes fall, what happens in the markets for inferior goods? (Correct answer: A)

a. prices and quantities both rise

b. prices and quantities both fall

c. prices rise and quantities fall

d. prices fall and quantities rise

My wrong answer: B

Summary

Chapter 3 is Interdependence and the Gains from Trade. This chapter explains one principle of Economics–Trade can make everyone better off. In order to explain it, I need to introduce three definitions first.

• Absolute advantage– the ability to produce a good using fewer inputs than another producer
• Comparative advantage– the ability to produce a good at a lower opportunity cost than another producer
• Opportunity cost– whatever must be given up to obtain some item

• This diagram means China could produce 80 iron ore or 100 cars.
• Australia could produce 70 iron ore or 50 cars.

As the diagram shows, China can produce both more iron ore and cars than Aus. That means China has absolute advantage in producing both goods. However, according to the definition of opportunity cost, the opportunity cost for China to produce an iron ore is 1.25 cars. (Because producing 80 iron core needs to abandon 100 cars). And the opportunity cost for Australia to produce 1 iron core is just 0.71 car. In other words, Australia has the comparative advantage in producing iron core.

This is the key to explain why trade can make everyone better off. Trade can make everyone in the economy produce goods with the lowest opportunity cost.

Definitions

1. Absolute advantage– the ability to produce a good using fewer inputs than another producer

2. Opportunity cost– whatever must be given up to obtain some item

3. Comparative advantage– the ability to produce a good at a lower opportunity cost than another producer

4. Imports– goods produced abroad and sold domestically

5. Exports– goods produced domestically and sold abroad

Review

I did all questions correctly! Excellent!

Summary

Chapter 2 is Thinking Like an Economist. This chapter shows two kinds of economic models, some history stories about Economics and many examples to explain the way of how economists think.

Economic models

The circular-flow diagram

• You can see how dollars flow among households and firms in the economy.
• In the markets for goods and services, firms are sellers and households are buyers.
• In the markets for factors of production, firms are buyers and households are sellers.

The production possibilities frontier/curve

• This is a curve to explain opportunity cost, efficiency, inefficiency and unachievable.
• As the diagram shows, the points A,B and C stand for efficiency. The point X is inefficiency and the point Y is unachievable.
• The point A moves towards the point C means the opportunity cost of some cottons are some amounts of wines.

The way of economists think

The phenomenon of ticket resale.

Lawmakers sometimes try to prohibit reselling tickets, or “scalping” as it is sometimes called, in order to keep the ticket price low. However, many economists side with the scalpers rather than the lawmakers. They think the ticket price without scalping cannot show the real value of the ticket. The rule influences market force(the invisible hand).

• Laws that limit the resale of tickets for entertainment and sports events make potential audience members for those events worse off on average.

  Definitions

1. Circular-flow diagram– a visual model of the economy that shows how dollars flow through markets among households and firms

2. Production possibilities frontier– a graph that shows the combinations of output that the economy can possibly produce given the available factors of production and the available production technology

3. Microeconomics– the study of how households and firms make decisions and how they interact in markets

4. Marcoeconomics– the study of economy-wide phenomena, including inflation, unemployment, and economic growth.

5. Positive statements– claims that attempt to describe the world as it is

6. Normative statements– claims that attempt to prescribe how the world should be

Review

I did all questions correctly! Excellent!

Summary

Chapter 1 is Ten Principles of Economics. These 10 principles can be divided into three parts and I write some examples to explain them.

How People Make Decisions

1.People face trade-offs.

2.The cost of something is what you give up to get it.

These two principles explain opportunity cost (the next best alternative forgone for an economic decision). Why we should use this concept? Here is an example about considering the cost of studying in a university. Some people may calculate the cost like tuition fee and meal fee. However, it is wrong because you still need to use meal fee for meals if you don’t go to a university. Besides, you don’t calculate your cost of time.

3.Rational people think at the margin.

Margin change means a small incremental adjustment to a plan of action. For instance, if a plane ticket costs 500 dollars, it should sell a ticket with the price greater than 500 dollars to earn profits. However, if there is a free seat and no one would reserve it, it could be sold with the price smaller than 500. Why? Because in this case, the marginal benefit is the price of that ticket, and the marginal cost is the oil used by plane to carry one more passenger (it could be ignored). In other words, it is profitable when the marginal benefit is greater than the marginal cost.

4.People respond to incentives.

e.g The law of demand. (The higher the price, the lower the quantity demanded and vice versa.) People respond to incentives so they could get more profits.

How people interact

5.Trade can make everyone better off.

Because countries can specialize in what they are good at. In other words, producing goods with the lowest opportunity cost.

6.Markets are usually a good way to organize economics activity.

7.Governments can sometimes improve market outcomes.

These two principles explain mixed economies and introduce the invisible hand–market, which can allocate resources efficiently.

How the Economy as a Whole Works

8.A country’s standard of living depends in its ability to produce goods and services.

9.Prices rise when the government prints too much money.

10.Society faces a short-run trade-off between inflation and unemployment.

Increasing the amount of money in the economy stimulates the overall level of spending and thus the demand for goods and services.
Higher demand may over time cause firms to raise their prices, but in the meantime, it also encourages them to hire more workers and produce a larger quantity of goods and services.
More hiring means lower unemployment.

###Definitions

1. Scarcity– the limited nature of society’s resources

2. Economics– the study of how society manages its scarce resources

3. Efficiency– the property of society getting the most it can from its scarce resources

4. Equality– the property of distributing economic prosperity uniformly among the members of society

5. Opportunity cost– whatever must be given up to obtain some item

6. Rational people– those who systematically and purposefully do the best they can to achieve their objectives

7. Marginal change– a small incremental adjustment to a plan of action

8. Incentive– something that induces a person to act

9. Market economy– an economy that allocates resources through the decentralized decisions of many firms and households as they interact in markets for goods and services

10. Property rights– the ability of an individual to own and exercise control over scarce resources

11. Market failure– a situation in which a market left on its own fails to allocate resources efficiently

12. Externality– the impact of one person’s actions on the well-being of a bystander

13. Market power– the ability of a single economic actor(or small group of actors)to have a substantial influence on market prices

14. Productivity– the quantity of goods and services produced from each unit of labor input

15. Inflation– an increase in the overall level of prices in the economy

16. Business cycle– fluctuations in economic activity, such as employment and production

###Review

There are some exercises in this book. I recorded questions I didn’t answer correctly here.

1.Your opportunity cost of going to a movie is_____(Correct answer: C)

a. the price of the ticket

b. the price of the ticket plus the cost of ant soda and popcorn you buy at the theater

c. the total cash expenditure needed to go to the movie plus the value of your time

d. zero, as long as you enjoy the movie and consider it a worthwhile use of time and money

My wrong answer: D

2.Because people respond to incentives,_____(Correct answer: D)

a. policymakers can alter outcomes by changing punishments or rewards

b. policies can have unintended consequences

c. society faces a trade-off between efficiency and equality

d. All of the above

My wrong answer: A

3.Adam Smith’s “invisible hand” refers to_____(Correct answer: D)

a. the subtle and often hidden methods that businesses use to profit at consumers’ expense

b. the ability of free markets to reach desirable outcomes, despite the self-interest of market participants

c. the ability of government regulation to benefit consumers even if the consumers are unaware of the regulations

d. the way in which producers or consumers in unregulated markets impose costs on innocent bystanders

My wrong answer: B

Backgrounds and my responsibility

In the beginning of Grade 10, my class advisor asked me to be the Class Sanitation Commissioner. It is a job to manage the students to clean our classroom and deliver meals from canteens to our class. Originally, my class advisor let me to do this simply because I was the only one who lived in the school dormitory since this job was time-consuming. (The Class Sanitation Commissioner needed to supervise students to do their work after school.)

What I did at first

At the beginning, I needed to make a table to make sure each student in our class had their position (like sweeping the floor in Monday or cleaning the blackboard in Wednesday). But I made a mistake at that time–I let my classmates choose the positions they want. After I asked them to choose positions they want in our QQ group online, I realized I shouldn’t do that. Obviously, some classmates complained that they wanted to do another work, and the process of choosing students was time-consuming. Finally, our monitor advised me to redistribute positions by myself and I did it.

What I have learned from it

Sometimes I should think twice before making a decision. Tell you the truth, when I redistributed the positions, some of my classmates argued with me. That was my fault because I let them choose work they want before.

The cooperation between two Class Sanitation Commissioners

As time passes, our class advisor realized it was difficult for one Class Sanitation Commissioners to do all works so she asked another student to do this work as well.
Generally speaking, we didn’t split the responsibilities the Class Sanitation Commissioner should take into two totally different parts. Some classmates used to say it was not wise to do so because we may ask the other Class Sanitation Commissioner to bear responsibilities. However, as something wrong in our classroom (about sanitation), one of us would bear the duty actively when the other one was absent.

By the way, thanks to this experience, I even made friends with another Class Sanitation Commissioner, Jason. We discuss tough questions in the spare time.

What we and I did during this year

Except stuffs I have mentioned before, the obligations also include passing the check from school supervisors every week and taking the disinfectant from another building every day.
It is worth mentioning that our class pass each check excellently.

Each year, our school asks us to choose one person who bears the most obligations and provides the greatest services for students in each class. Obviously, the Class Sanitation Commissioners take more duties than others. And I take the disinfectant every day, that means I bear a little bit more duty than another Class Sanitation Commissioner, Jason.

You could see a picture below. In the blank of Rewards and punishment record, you will see “Outstanding Student Leader” in Chinese.

My feelings

Through being a Class Sanitation Commissioner is really exhausting, I was still grateful to get this opportunity. I strengthened my ability to lead others to bear their own duty. During this process, I developed the spirit of helping my classmates and bearing responsibilities actively. Besides, I got to know how to communicate with classmates efficiently and kindly. Sometimes students may be angry about duties they have. They may think it is unfair and complain it with Class Sanitation Commissioner. In order to avoid getting into trouble (like arguing), it’s important for us to handle such things properly. I used to go mad easily, now I’m much better in terms of controlling my feelings. Last but not least, I have learned how to organize students to do suitable work. For example, students in our class thought it was easy to clean the blackboard so they all chose to do this work. And I chose someone who wasn’t capable enough to do other work to clean the blackboard.

Backgrounds

Our A-level center organized an event to let Grade 9 students who wanted to study in our center learn more about our center. During this event, our teachers set different lessons and Grade 9 students could choose what they were interested in. In order to let them have better experience during the lessons, our A-level center also asked its students to take part in the lessons and help them.

What I did

I was proud of taking part in the Chemistry lessons because our Chemistry teacher chose students by herself instead of choosing students randomly. (Actually, all teachers except Chemistry teacher chose students to take part in their classes randomly.) During the Chemistry lessons(actually, we had three same lessons at that time), I needed to help students do an experiment called titration.

Introduction: what is titration

Titration is used to indicate the concentration of an unknown solution, which is usually used in acid-base titration.

The actual end point of the titration usually adds slightly more amount of solution than it need to ensure the other solution is fully reacted.

In acid-base titration, we often use litmus, methyl orange and phenolphthalein as indicator.

My preparation

Truth to be told, titration is an experiment in the A-level Chemistry practical paper syllabus. In other words, students in Grade 11 had already did it in their A-level examinations. But thing is that, as Grade 10 IGCSE students, I only knew the theoretical knowledge about this experiment. In addition, I was not good at doing experiments on my own. I even felt scared of using a burner! In other words, it must be a challenge for me to do this experiment.

Practicing it in advance

Our teacher found the spare time and let us do the titration experiment in the school laboratory in advance. She taught us the theoretical knowledge first (and I had acquired it before), then she let us do the experiment step by step and guided students.

Here is a photo from our Class Advisor.

Review and improve the experiment

It was hard for us to use the burette and pipette. We hadn’t used it before and the way to use them was a little bit complex. I practiced the way to use them for three times in order to master it.

My feelings

I was proud of getting the opportunity to do this titration experiment. Firstly, titration is an experiment in the A-level Chemistry examination syllabus. I practiced it for my A-level Chemistry examination in advance. Secondly, I am poor in doing the experiment on my own. (It is not my fault but the problem the majority of Chinese students have. In Chinese, Chemistry exams don’t involve practical experiments, leading to a fact that most of us are poor in it.) However, if you want to study Chemistry in the universities all around the world, it’s important to develop skills of doing the practical experiment. But we cannot access the chemical laboratory to practice them in our daily life. In other words, today’s titration experiment was a valuable experience for me.

Why I do it

I have used Github for several months (although I just updated articles recently). Actually. my original purpose of using Github is just to record contests and extra-curriculums I did and show my feelings about them. However, thanks to Github, I was interested in recording my daily life gradually. In addition, I write this article to thank for one of my friends, Justin, who helped me a lot to give me technical support about how to use Github.

My feelings of using Github (Programming part)

Tell you the truth, it’s quite difficult for me to set my own Github repository since i don’t have the gift for programming. It is worth mentioning that Github is not suitable for the Greenhand, since it needs complex codes to operate. I used to search information online to set my Github blog（it took me nearly two weeks, but I was not totally successfully– I didn’t know how to send my articles to Github! Anyway, at least I developed my skills of self-study and searching information during this process.

My feelings of using Github (Writing articles part)

With my friend Justin’s help (I will mention it later), I could push my articles to my Github easily. I was proud of my Github whenever I see the layout of it is fantastic (at least I think so). In addition, I have a sense of achievement when I see my articles on it.

What’s more, I have been developing the habit of recording my daily life gradually. I was surprised when I saw my previous experience (I nearly forgot half of them). I used to think that keeping diaries is just a waste of time. Thanks to Github, I found it was quite meaningful.

Finally, i must mention that my English writing skill is improved. Some of my classmates were confused why I didn’t use my mother tongue to write articles on Github. I wanted to strengthen my ability to write English articles and obviously I wouldn’t lose this chance.

My contributor Justin and more

I am grateful to Justin for his helping hand. Generally speaking, I could say that I cannot use Github so comfortably without Justin’s help.

First, he made a linkage to my repository, that means I can push my articles to Github much easier.

Besides, he helped me to change the theme in Github. The theme in Github can be described as a format you used in your Github. Each format has its own pictures and layout. Justin let me look through some websites to choose a theme l love, (Without his guide, I even couldn’t find the websites to download themes) then he changed the theme by himself. （I just loved a few themes, but he was so patient that he helped me to choose a reliable theme. In addition, it was time-consuming and complex to change a theme, I even didn’t how to change it.）He also taught me many useful skills such as judging which theme was good by looking through the functions it has. I used to judge it only by which picture it had was beautiful.

Last but not least, I also acquired quite a great amount of useful knowledge about Computer Science from Justin. For example, the way how the Github operates. I used to simply learn how to use Github, but I did never think about what is Github before Justin teaching me.

Conclusion

I was keen on updating articles on Github, not only i loved recording my daily life, but also I met my friend Justin through Github.