Question

O'Neal works hard. He is often seen _______ heavily before his teammates have even arrived at practice.

A. sweated                    B. to be sweated   

C. sweating                   D. being sweated

Answer 1

C

解析:

非谓语动词的考查是本题的目的。see somebody doing表示看见某人一直正在干某事，题干中只是将主动变成了被动。