Complete the following statements with proper words or expressions according to the course book.Unlike free phrases, the structure of an idiom is to a large extent( ).
Complete the following statements with proper words or expressions according to the course book.Unlike free phrases, the structure of an idiom is to a large extent( ). 【正确答案】：UNCHANGEABLE 【题目解析】：与自由短语不同，成语的结构在很大程度上是不变的。
