句型转换。

1. I received a letter from my friend last week. (改为同义句)

    I ______ ______ my friend last week.

2. She is too short to reach the top of the blackboard. (改为同义句)

    She is not _______ _______ to reach the top of the blackboard.

    She is _______short _______ she can't reach the top of the blackboard.

3. Please take this medicine twice a day. (就划线部分提问)

    _______ ______ do I have to take this medicine?

4. Must I finish my homework now? (进行否定回答)

    No, you don't ______ ______.