Often visible as smog, ozone is formed in the atmosphere from hydrocarbons and nitrogen oxides, two major pollutants emitted by automobiles, react with sunlight.
Often visible as smog, ozone is formed in the atmosphere from hydrocarbons and nitrogen oxides, two major pollutants emitted by automobiles, react with sunlight. (A) ozone is formed in the atmosphere from (B) ozone is formed in the atmosphere when (C) ozone is formed in the atmosphere, and when (D) ozone, formed in the atmosphere when (E) ozone, formed in the atmosphere from 这道题本人对于OG上的解释不太理解,D,E在OG上解释是说缺少谓语,那么formed难道不是谓语吗?