Often visible as smog, ozone is formed in the atmosphere from hydrocarbons and nitrogen oxides, two major pollutants emitted by automobiles, react with sunlight.
ozone is formed in the atmosphere from
ozone is formed in the atmosphere when
ozone is formed in the atmosphere, and when
ozone, formed in the atmosphere when
ozone, formed in the atmosphere from
A from介词后面不能跟句子,只能+名词
答案是B 哦登录 或 注册 后可以参加讨论