og 68 and when ？

cdoublesok

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/row, 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.

c有什么问题，看不太明白解释？请nn们解释一下。a的from为什么说是不符合语法的？

jennifer1979

句子后面有个react 动词。所以H 和N是这个REACT的主语。如果用FROM就不成句子了。and when是同一个道理。

nickt

C 的意思是Ozone（有两种形成方式），在大气层中形成的，以及当XX和YY起反应时。。。

A的from在部分看不出太大问题，但在整个句子里显的不合

EASYSUMMER

C 的错误就是改变了原意。

我有个低级问题也想让大家帮忙：

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, 这个结构叫什么？？是独立。。结构还是？？ 这里是不是省了 BE 。有什么规律？？

多谢！

titatita

以下是引用EASYSUMMER在2005-6-13 5:44:00的发言：

C 的错误就是改变了原意。

我有个低级问题也想让大家帮忙：

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, 这个结构叫什么？？是独立。。结构还是？？ 这里是不是省了 BE 。有什么规律？？

多谢！

形容词做定语在句首修饰主语ozone

补全是ozone which is often visible as smog...

titatita

以下是引用cdoublesok在2005-3-17 19:07:00的发言：

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/row, 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.

c有什么问题，看不太明白解释？请nn们解释一下。a的from为什么说是不符合语法的？

把原句的因果关系,当h和n在阳光下互相作用时形成了ozone改成了并列关系,ozone is formed..., and when..

snowfield

C改变了句子的意思，这一点无异议，og11对c地分析也仅从这一角度出发进行的。我觉的除了上述意思的问题，c还存在以下语法问题：我觉得and之前也不能有逗号，因为从意思上看and之后的when从句可以和in the atomsphere平行来作为主句的状语，即when从句和主句不是并列关系，而是从属关系，所以不能用and连接，但是如果去掉and之前的逗号。我觉得从语法上来讲，好像就没有问题了。

请NN指正。

hyh_0927

(E)
            ozone, formed in the atmosphere from
                

為什麼OG說選E會造成SENTENCE FRAGMENT呢?

為什麼OG說選E會造成SENTENCE FRAGMENT呢?

yaomao

我是这样想的
如果E对的话，主干就变成了ozone react with sunlight，
语法上就有问题了，ozone是单数，但谓语动词react用的是复数
所以OG会说这个是sentence fragment吧

晴天小狗

同意snowfield，这里主句与从句不能并列

另外，E选项中，formed是分词，不是谓语。本句中没有谓语所以是fragment