Many of the audience ______ asleep when they ______ the lecture.[ ]

A. fell; were hearing

B. were falling; heard

C. had fallen; heard

D. fell; had heard

35W电烙铁的35W是指该电烙铁的（）。

A.最小功率

B.最大功率

C.平均功率

D.与功率无关