根据英语句子写出动物短语的意思（请写整句）
1.The plan is good enough to kill two birds with one stone.
2.When the teacher came in,everyone was as quiet as a mouse.
3.It's raining cats and dogs outside.
4.Don't believe him.He is a wolf in sheep's clothing.
5.She is 16 years old and ugly ducking has grown into a swam.