________to sunlight for too much time will do harm to one’s skin.

________to sunlight for too much time will do harm to one’s skin.
A.Exposed B. Having exposed
C.Being exposed D. Afterbeing exposed
请教你，哪一个是正确的选择，为什么？

答案是C 动名词的被动形式作主语 相当于抽象名词作主语
选项AD过去分词 和介词短语 不具备名词特征 故不能作主语
选项B 是动名词的完成形式 与句意不符 故错

------ to sunlight far too much time will do harm to one's skin . 选c。该题考查动词-ing短语作主语的用法。expose的逻辑主语是one's skin，因此，要用被动结构。