Hi Le, The first two sentences mean the same thing. I can only speak for the United States when I say this, but when someone is being "groomed", it means they are getting special training for their particular sport, industry, etc. Commerce is "the activity of buying and selling, especially on a large scale." So if you go to the store and buy a candy bar, you are participating in commerce. In the same vein, if you place a business order for 10,000 candy bars, you are participating in commerce. Business is a term used for many things. The definition is "a person's regular occupation, profession, or trade." Business is used in a lot of daily life in the United States. You could ask someone, "What business are you in?" The economy is the overall market. Think big, like a stock market. Every country has an economy, the world has an economy. Let me know if you have any more questions!