These chairs may look good,but they’re very uncomfortable _____.

问题描述:

These chairs may look good,but they’re very uncomfortable _____.
A.to sit on B.to be sat on C.sit on D.sitting on 为什么不选择”B"呢

这是不定式主动表被动
因为不定式to sit on 的逻辑主语是人,人和坐下是主动关系