When he was a boy, he used to go there and watch ____

When he was a boy, he used to go there and watch ____
A、to repair bicycles
B、bicycles to be repaired
C、bicycles being repaired
D、repairing bicycles
【正确答案】：C
【题目解析】：【考点点击】本题考查v.-ing的被动形式。【要点透析】此处为-ing形式一般式的被动语态作宾语补足语,强调自行车被修理的过程。