用所给动词的适当形式填空
1.The children will have great fun ________ (feed) animals in the zoo.
2.He liked to tell funny stories to make people ________ (laugh)
3.He ________ (not hurt) himself if he ________ (be) careful enough.
4.He tried but failed ________ (open) the door.
5.Don’t worry. We’ll do what we can ________ (pass) the exam.