问题
选择题
Some very common things such as to the sun for a long time will do harm to people's skin and even cause skin cancer
A．exposing
B．being exposed
C．having exposed
D．exposed
答案
答案：B
题目分析：考查动名词做主语，句意：一些非常普通的事情，如暴露在太阳下面很长时间，会对人的皮肤有害甚至造成皮肤癌。Will do是这句话的谓语，前面是主语，用动名词做主语，be exposed….，是“暴露于”，选B。