1. hot-button topic 非常敏感的话题

2. as cool as cucumber镇定自若的

3. a piece of cake 很简单的事

4. cry over spilt milk 覆水难收

5. it's my cup of tea 符合我的口味

6. the world is your oyster 随心所欲

7. two peas in a pod 十分相似

8. bear fruit 奏效