题目内容：

根据句意，写出括号内所给单词的适当形式。

1.The fans are waiting for the two famous __________ (女演员), Sun Li and Fan Binbin.

2.When an earthquake happens, we should run to __________ (安全) as quickly as possible.

3.Each group should __________ (提交) a report to the teacher after the survey.

4.Life is too busy, and sometimes it will let me breathe __________ (沉重地).