帮忙解释为什么选哪个选项_______ the polluted air is dangerous for our health.A.Exposing B.Exposed C.Being exposed D To expose

帮忙解释为什么选哪个选项_______ the polluted air is dangerous for our health.A.Exposing B.Exposed C.Being exposed D To expose
帮忙解释为什么选哪个选项
_______ the polluted air is dangerous for our health.
A.Exposing B.Exposed
C.Being exposed D To expose

帮忙解释为什么选哪个选项_______ the polluted air is dangerous for our health.A.Exposing B.Exposed C.Being exposed D To expose
C.表被动

D 不定式做主语

选c
“使...暴露于...（环境）之中，使...和...接触”，常用被动语态：be exposed to sth
如：Being exposed to sunsunshine for too much time will do harm to one's skin.
长时间日晒会对皮肤对不利。

选D ,To expose 使处于……作用下

动词不定时作主语，改为这样应该好理解一点：it is dangerous for our health to expose the polluted air 。此句为it作形式主语，题中只是把主语还原了