giup a

`71. D`

`-` Dẫn chứng: 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.

`72. C` 

`-` stamp collecting can make you famous không có trong bài 

=> chọn C

`73. C` 

`-` Dẫn chứng: 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.

`74. D`

`-` business: kinh doanh ~ ~ hoạt động mua và bán

`75. B` 

`-` Dựa vào đoạn văn rồi suy luận.