It was the president's speech that the secretary spent the whole morning at home.A. to p

问题补充：

It was the presidents speech that the secretary spent the whole morning at home.

A. to prepare

B. preparing

C. prepared

D. be prepared

答案：

A. to prepare

(答案→)B. preparing

C. prepared

D. be prepared

解析：本题中含有一个强调句型，强调的是句子的宾语preparing the presidents speech；在英语中，通常动名词可以在句中做宾语。本句中是一个固定搭配spend some time in doing stt花费时间做某事；句义：秘书花了整个晚上在家里准备的正是总统的演讲。故B正确。