banana skin
noun
1- the skin of a banana, especially when peeled off and discarded（尤指剥后被弃的）香蕉皮。
1.1
- informal used to refer to a cause of difficulty or embarrassment〈非正式〉困境, 窘境：
the insurance market has an unhappy knack of slipping on banana skins.
保险市场不幸常要遇上困境。