题目内容：

spend
The chief executive officer was unwilling to spend his time on _____ a detailed advertisement presentation.
A.preparation
B.prepared
C.preparing
D.to prepare
答案居然选C,但是不是spend in doing sth,和spend on

优质解答

恕我直言,你学得太教条了,spend in doing sth,和spend on sth是没错,但是也还有其它形式的用法：spend some time on doing sth,意思是花时间做某事,总的来说,spend是那种后面只能跟动名词或名词的动词,所以肯定不选B...