It was not until near the end of the letter she mentioned her own plan.A. whereB. thatC.

问题补充：

It was not until near the end of the letter she mentioned her own plan.

A. where

B. that

C. why

D. when

答案：

A. where

(答案→)B. that

C. why

D. when

解析：句意为：一直到信的结尾他才提到他自己的计划。强调句型的基本结构为：It is +被强调部分+that+剩余部分。判断是否为强调句型的方法，把It is 与that去掉组成完整的句子结构，即为强调句型，由此可知本句属于强调句型，故答案为B。

考点: 考查强调句型的用法。