PREP-162，请指教

estherpeter

这题E为什么不对呢

读起来感觉也挺顺的

wei_wangyan

以下是引用estherpeter在2007-4-23 21:32:00的发言：

这题E为什么不对呢

读起来感觉也挺顺的

E. they act as a global thermostat to thus keep Earth from either burning up or freezing over, but they also accelerate

thus副词不能连接并列的谓语act, keep（应将to改为连词and）

estherpeter

以下是引用wei_wangyan在2007-4-24 9:12:00的发言：

E. they act as a global thermostat to thus keep Earth from either burning up or freezing over, but they also accelerate

thus副词不能连接并列的谓语act, keep（应将to改为连词and）

E. they act as a global thermostat to keep Earth from either burning up or freezing over, but they also accelerate

act和keep一定要用and平行吗? 如上, act as...to keep 不可以吗?

wei_wangyan

以下是引用estherpeter在2007-4-24 9:59:00的发言：

E. they act as a global thermostat to keep Earth from either burning up or freezing over, but they also accelerate

act和keep一定要用and平行吗? 如上, act as...to keep 不可以吗?

看来是可以的，但E的确是改变了原文要表达的意思。

162. Although ice particles in the upper atmosphere benefit Earth in that they reflect and absorb solar radiation, acting as a global thermostat and thus keeping Earth from either burning up or freezing over, they also accelerate the destruction of the ozone layer by reacting with chlorofluorocarbons (CFC's).

原文的acting and keeping是作benefit的伴随状语，解释如何benefit Earth。Although ice particles benefit..., they also accelerate the destruction... 原文要表达这样一个对比：尽管有益，也有害。

E. they act as a global thermostat to thus keep Earth from either burning up or freezing over, but they also accelerate

而E呢，如果这样的句子结构不算错，那它表达的意思也不符合逻辑。

Although ice particles benefit..., they act to keep...这两个分句之间本来没有这层让步转折含义（原文的关系应该算是递进吧），但因为they act...成了独立的句子，所以与前面的although状语从句联合，就不符合逻辑意思了。

再往后面的but... 又与although重复了（重复使用连词）。

这样一分析，觉得自己原来的问题想得更明白了。谢谢MM。

bestway

参考：

179.
                During the early years of European settlement on a continent that was viewed as “wilderness” by the newcomers, Native Americans, intimately knowing the ecology of the land, were a help in the rescuing of many Pilgrims and pioneers from hardship, or even death.

(A) Native Americans, intimately knowing the ecology of the land, were a help in the rescuing of

(B) Native Americans knew the ecology and the land intimately and this enabled them to help in the rescue of

(C) Native Americans, with their intimate knowledge of the ecology of the land, helped to rescue

(D) having intimate knowledge of the ecology of the land, Native Americans helped the rescue of（C）

(E) knowing intimately the ecology of the land, Native Americans helped to rescue

Choice A suffers from the wordy and indirect expression were a help in the rescuing of. B creates an awkward, redundant, fused sentence in which the first clause has to be repeated in the vague this of the second clause; furthermore, the comma required before and in larger compound sentences is omitted. D and E are confusingly worded because they begin with present participles (having and knowing) that appear at first to refer to the immediately preceding noun, newcomers, rather than to Native Americans.
                D also has the wordy and unidiomatic helped the rescue of. Clear, direct, and economical, choice C is best.

觉得A的修饰也存在歧义，但就意思逻辑上来说，A也的确比E好。