Which of the following is NOT one of the rhetoric characteristics of idioms in general?（ ）
A、Stylistic features.
B、Syntactical features.
C、Rhetorical features.
D、Occasional variations.
【正确答案】：B
【题目解析】：To use idioms properly, one needs to know the rhetoric characteristics of idioms such as stylistics features, rhetoric features and their occasional variations. 关于分类的定义不含B选项