The professor paused as if his students to ask questions on the point he had just made.A

网友回答

(答案→)A. expecting
B. is expecting
C. expected
D. to have expected
解析：考查时态。句意：这位教授暂停了一下，好像正盼望着他的学生回答他刚才提出的问题。结合语境可知从句中描写的是刚才发生的动作，故用过去进行时态，这句话省略了he was，选A。