He is not careful.He went to school in _____shoes,but not ____ones

题目

He is not careful.He went to school in _____shoes,but not ____ones
A.a pair of,a couple of B.a pair of ,a pair of C.a couple of ,a pair of D.a couple of a couple of 选择哪个?帮我解析下

答案

选C
译文：他很粗心,他穿了两只鞋去上学,但不是一双.
a pair of:一双,一对,例如：a pair of trousers:一条裤子; a pair of glasses:一副眼镜
a couple of:两个,两样（可以指人或者物）,例如：a couple of friends:两个朋友