to sunlight for too much time will do harm to one’s skin, so you should make it a rule to get your skin creamed before going out in summer.
A. Exposed
B. Having exposed
C. Being exposed
D. To expose
网友回答
A. Exposed
B. Having exposed
(答案→)C. Being exposed
D. To expose
解析：句意：过长时间暴露于阳光下会对人的皮肤造成损伤，因此，夏天外出前涂上防晒霜应该成为你的习惯。根据will do harm to是主句谓语确定空处应该是句子主语。A项不能做句子主语，排除；根据句意应是被暴露于阳光下，应是被动，B和D是主动，也排除。故C正确。