The secretary worked late into the night a long speech for the president. A. to prepareB

问题补充：

The secretary worked late into the night, a long speech for the president.

A. to prepare

B. preparing

C. prepared

D. was preparing

答案：

A. to prepare

(答案→)B. preparing

C. prepared

D. was preparing

解析：考查分词做状语。本题中的动词prepare与句子主语the secretary构成主动的关系，故使用现在分词表示主动和正在进行。句意：那个秘书一职工作到深夜，为主席准备一个很长的发言稿。故B正确。