Ⅰ. 用所给词的适当形式填空(10分)
1. The boy is too young to know the (dangerous)of smoking.
2. Be careful (not fall)off the ladder.
3. The Blacks picked up their (knife)and forks to have family dinner together.
4. I am (worry)about the result of the exam.
5. Remember (close)the door when you leave the room.
答案: 1. danger 2. not to fall 3. knives 4. worried 5. to close
