6. a ............... the
⇒ "a" chưa xác định, còn "the" xác định bức thư là của chị cô ta
7. the.............the
⇒ vật cụ thể thì dùng "the"
8. ko điền hoặc sửa "learn" thành "learning"
⇒ learning+môn học
9. the
10. the...............the
⇒ "earth" và "sun" chỉ có một
II.
1. I was so tired that I couldn't go to school.
2. He is such a strong man that he can carry 100 kilos
3. She is too small and weak to do these hard work
4. The shelves are big enough for them to arrange many kinds of books
5. These are such ripe apples that we have to eat them immediately
6. My brother is intelligent enough to do all difficult exercises