1. a piece of cake 小菜一碟
eg :The math test was a piece of cake .
数学考试对我来说小菜一碟。
2. once in the blue moon 很少
eg : We go out once in a blue moon .
我们很少出去。
3. on cloud nine 超开心
eg: When my father bought me a mobile phone ,I was on cloud nine .
我爸给我买手机的时候，我超开心的！
4. have a bigger fish to fry 有更重要的事做
eg: I couldn’t attend the meeting.I had bigger fish to fry .
我还有要事，不能来参加会议了。
5. to go bananas 抓狂
eg: She went bananas when she found him cheating.
她发现自己被他骗了的时候气得要命。
6. break a leg 祝好运
eg: All you have to do now is relax. Break a leg !
你现在需要做的就是放松，祝你好运！
7. call it a day 结束
eg: Let’s call it a day .
这一天终于过完了！
8. get the boot 被解雇
eg: I got the boot today.I have to find a new job.
我今天被炒了，要找新工作了。
9. bring home the bacon 赚钱养家
eg：My father has a good job and he brings home the bacon .
我爸收入可观，他负责赚钱养家。
10. all in one piece 安然无恙
eg: She got home from the party all in one piece .
她从派对全身而退。
大家如果有其他英语知识，也可以分享给我哦[作揖]