1. 用方框中所给短语的适当形式填空。

play a part    be able to    fall down    look for

1. （1） I am my pet dog. I can't find it anywhere.
3. （2） In the future, robotsdo lots of dangerous work.
5. （3） I think we mustin protecting wild animals.
7. （4） The tall buildingand many people got hurt.