【题目】He was seen ________ football with his classmates there.
A.play
B.to play
C.played
D.being played

【答案】B
【解析】考查非谓语动词。句意：他被看见在那儿和同学们踢足球。see sb. do sth.“看见某人做了某事”，主动语态中省去to，被动语态要补出to，故选B。