Is it the e-mail that you got yesterday_____makes you so sad?

题目

Is it the e-mail that you got yesterday_____makes you so sad?
A.which B.what C.that D.when

答案

选C,强调句的疑问句型,固定搭配it is ...+that,前面的that为定语从句标志,可以省略.整句话可以改为正常有序为It is the e-mail （which) you got yesterday that makes you so sad.