It is only you understand what your parents do to you you can improve your relationship with your parents.
A. that; what
B. when; that
C. which; where
D. how; what
网友回答
A. that; what
(答案→)B. when; that
C. which; where
D. how; what
解析：考查含有状语从句的强调句型。强调句型的结构为：it is+ 被强调的部分+ that+ 其它，此题中强调的是一个时间状语从句when you understand what your parents do to you，第二空用that，是强调句型的标志，所以选B。