I. 根据句意填空。
1. I can’t pass the English exam. I f_________ very sad.
**2. You must listen to the teacher _________ in class.
**3. Listen! The old man is ________ what’s happening to the house.
4. I can’t find my key. It is ________.
5. There is snow all ________. Please clean it.
*6. Fish can’t live ________ water.