Read the passage carefully and choose the correct answer. Stamp collecting is an interesting hobby. You can learn many things, such as the geography of a country from stamps. Postal stamps are a source of interesting facts and important dates about every country in the world. It makes stamp collecting become very popular. As you look at the pages of a stamp album, you can learn interesting details of foreign customs, arts, literature, history and culture. Their colours can make you feel relaxed ...

Read the passage carefully and choose the correct answer.

Stamp collecting is an interesting hobby. You can learn many things, such as the geography of a country from stamps. Postal stamps are a source of interesting facts and important dates about every country in the world. It makes stamp collecting become very popular. As you look at the pages of a stamp album, you can learn interesting details of foreign customs, arts, literature, history and culture. Their colours can make you feel relaxed and happy. Collecting stamps can become a business. If you are lucky in finding a special stamp, it will bring you some money besides knowledge and pleasure.

Question: The main idea of the passage is____