68. 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
我想問的是D
可不可以句子還原成:
ozone, often visible as smog, formed in the atmosphere when ....???
我不知道D錯在哪裡 |