Doing your homework 请进

题目

Doing your homework 请进
Doing your homework is a sure way to improve your test scores,and this is especially true ___ it comes to classroom tests.
A.before B.since C.when D.unless
具体讲讲选什么,有什么语法知识没?
应选C,原因?

答案

C
when it comes to sth：这是一个固定搭配,意思“在...方面”
例如：When it comes to English speaking,I am always the first in my class.
在英语方面,我在班里总是第一.