og13 97 真心求教~~~

靓linda

97. Some anthropologists believe that the genetic homogeneity evident in the world's people is the result of a "population bottleneck"—at some time in the past our ancestors suffered an event, greatly reducing their numbers and thus our genetic variation.
(A) at some time in the past our ancestors suffered an event, greatly reducing their numbers
(B) that at some time in the past our ancestors suffered an event that greatly reduced their numbers
(C) that some time in the past our ancestors suffered an event so that their numbers were greatly reduced,
(D) some time in the past our ancestors suffered an event from which their numbers were greatly reduced
(E) some time in the past, that our ancestors suffered an event so as to reduce their numbers greatly,
答案选c
选项a中有句解释不太理解
The structure makes that clause appera to be an awkward and rhetorically puzzling suparate assertion that the writer has appended to the prior claim about what the anthropologists believe. The agent or cause of reducing is unclear.
求大牛小牛们指点~~谢谢~~

靓linda

From beatthegmat：
In answer choice (A) there is a problem with modification. (A) is implying that our ancestors greatly reduced their own numbers (this is incorrect because it was the event that greatly reduced ancestors). When we have an independent clause followed by a participle phrase分词短语 (one that starts with a gerund动名词 and serves as an adjective clause), the participle phrase modifies the subject of the sentence. 伴随状语从句
In non-grammarese: 'ancestors' is the subject of the independent clause, 'at some time...' and because of the comma after event, we have the incorrect meaning. It was not the ancestors but an event that 'reduced their numbers.'
Therefore, we want to make sure that it is clear that 'event' is 'greatly reducing the numbers.' One way to fix that is by using the relative pronoun 'that.' In (B), we have 'an event that greatly reduced their numbers' that does a good job of correcting the error in (A). Therefore (B) is the answer.
我还想问的是，对于以上解释reducing不能作为结果状语修饰前面的 ancestors suffered an event？？

pinkking

看这个，后面-ing主语应该跟句子主语一致

在白勇书里，ing分词短语在句末
1）伴随动作：状态和功能，与句子的谓语动作同时发生，逻辑主语等于主句主语
2）伴随结果，整个句子是原因，到时分词动作产生，无逻辑主语

如果不明白建议看这个帖
http://forum.chasedream.com/GMAT_SC/thread-650744-4-1.html

靓linda

谢谢。。帮我回忆起来知识点了。。

看这个，后面-ing主语应该跟句子主语一致

在白勇书里，ing分词短语在句末
1）伴随动作：状态和功能，与句子的谓语动作同时发生，逻辑主语等于主句主语
2）伴随结果，整个句子是原因，到时分词动作产生，无逻辑主语

如果不明白建议看这个帖
http://forum.chasedream.com/GMAT_SC/thread-650744-4-1.html

-- by 会员 pinkking (2012/8/1 0:16:45)

靓linda

各位童鞋，帮忙解释一下顶楼的a选项的解释啦。。。欢迎欢迎，。。

靓linda

97. Some anthropologists believe that the genetic homogeneity evident in the world's people is the result of a "population bottleneck"—at some time in the past our ancestors suffered an event, greatly reducing their numbers and thus our genetic variation.
(A) at some time in the past our ancestors suffered an event, greatly reducing their numbers
(B) that at some time in the past our ancestors suffered an event that greatly reduced their numbers
(C) that some time in the past our ancestors suffered an event so that their numbers were greatly reduced,
(D) some time in the past our ancestors suffered an event from which their numbers were greatly reduced
(E) some time in the past, that our ancestors suffered an event so as to reduce their numbers greatly,
答案选c
选项a中有句解释不太理解
The structure makes that clause appera to be an awkward and rhetorically puzzling suparate assertion that the writer has appended to the prior claim about what the anthropologists believe. The agent or cause of reducing is unclear.
求大牛小牛们指点~~谢谢~~

-- by 会员 靓linda (2012/7/31 23:48:25)

真的不太能理解这句话。。。请大家帮忙解释。。

冷辰

对A的解释看不明白，难道 reducing their numbers and thus our genetic variation不是our ancestors suffered an event的结果吗？

在Ving的用法里面 S+V+O，Ving的用法有两个嘛，一个是describe the clause，对前一个分句作 补充说明，另一个是present result of the clause

这个难道不是第二种用法吗？

还有，OG对A的解释：that的缺失使得后一个claim是谁发出的显得unclear, 似乎是作者附加上去的信息。这又是为毛？谁给解释一下啊？

靓linda

the agent or cause of reducing is unclear.这个应该是指：reducing的逻辑主语应该是event，但是这里有事ancestor的嫌疑，有歧义，
The structure makes that clause appera to be an awkward and rhetorically puzzling suparate assertion that the writer has appended to the prior claim about what the anthropologists believe. 这句应该是指，破折号其实是in other words，后面跟的内容是前面believe内容的进一步解释，that不可缺，不然就断裂了吧。。。

靓linda

the agent or cause of reducing is unclear.这个应该是指：reducing的逻辑主语应该是event，但是这里有事ancestor的嫌疑，有歧义，
The structure makes that clause appera to be an awkward and rhetorically puzzling suparate assertion that the writer has appended to the prior claim about what the anthropologists believe. 这句应该是指，破折号其实是in other words，后面跟的内容是前面believe内容的进一步解释，that不可缺，不然就断裂了吧。。。

对A的解释看不明白，难道 reducing their numbers and thus our genetic variation不是our ancestors suffered an event的结果吗？

在Ving的用法里面 S+V+O，Ving的用法有两个嘛，一个是describe the clause，对前一个分句作 补充说明，另一个是present result of the clause

这个难道不是第二种用法吗？

还有，OG对A的解释：that的缺失使得后一个claim是谁发出的显得unclear, 似乎是作者附加上去的信息。这又是为毛？谁给解释一下啊？

-- by 会员 冷辰 (2012/8/5 14:44:23)

lcxpb

这题og选的是b呀，楼主弄错了吧~修改一下哇~~