true idioms
【正确答案】：Idioms consist of set phrases and short sentences, which are peculiar to the language in question and loaded with the native cultures and ideas. The true idioms of a language share three common features that differentiate them from plain and simple collocations: (1) They are not compositional, (2) Their words are not substitutable, and (3) They are not modifiable.
【题目解析】：本题考查第十章的习语true idioms在课本中没有明确给出，属于超纲部分，但是考生在学习中应该会总结。
