og 68 conj + conj 是不是错了?

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

In choice A, the construction from hydrocarbons and nitrogen oxides ... react is ungrammatical. In B, the best choice, the conjunction when replaces the preposition from, producing a grammatical and logical statement. In choice C, the use of the conjunction and results in the illogical assertion that the formation of ozone in the atmosphere happens in addition to, rather than as a result of, its formation when hydrocarbons and nitrogen oxide react with sunlight. Choice D omits the main verb, is, leaving a sentence fragment. E compounds the error of D with that of A.

，and when 是不是错了呢？ 好像从来没有见到过conj + conj + SVO.

谢谢大家

感觉上应该是因情况而定的：

比如这样的并列情况：when。。。，when。。。， and when。。。。

大家继续讨论

同意楼上说法。例子也很恰当。

只有起同样作用的连词连用才不可以。