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!

Hello again Le, Here are my answers to your questions: 1. The expression we would normally use here is "He is being groomed for stardom". This expression is almost idiomatic since the word groomed actually means to be be well presented and this is why we use this rather than "trained". If you want to become a star then your presentation is everything. 2. Commerce is the exchange of merchandise on a large scale between individuals or nations; Business is a commercial or industrial operation; Economy in this context could be described as the administration of the financial resources of an individual, community or country. I hope my definitions are understandable. Please let me know if not. Can I also point out a grammatical error in the wording of your questions: The meaning are same?.... should read The meanings are the same?... What is differences among.... should read What are the differences among... Note also the missing article (the) in each case. The plural forms of the verb and noun must match. Hope this has all been useful.