1.

a drop in the ocean.
沧海一粟。

2.

actions speak louder than words.
事实胜于雄辩。

3.

to add fuel to the fire.
火上浇油。

4.

the ball is in your court.
下一步就看你的了。

5.

to bend over backwards.
竭尽全力。

6.

to bite off more than you can chew.
贪多嚼不烂。

7.

by the skin of one’s teeth.
侥幸

8.

to cry wolf.
“狼来了“

9.

to cut to the chase.
开门见山地说吧。

10.

to get one’s head around something.
使某人对某事摸不着头脑