新人求助og18上的一道语法题

Ondksan

the north american moose's long legs enable it to move quickly through the wood, stepping easily over downed trees, but predators pursuing it must leap or go around them.A. moose's long legs enable it to move quickly through the wood, stepping easily over downed trees, but predators pursuing it must leap or go around them.与原句相同
B. moose's long legs enable it to move quickly through the wood, stepping easily over downed trees while predators pursuing them must leap or go around.
C. moose's long legs enable it to move quickly through the wood and to step easily over downed trees, but predators pursuing them must leap over or go around them.
D. moose has long legs, enabling it to move quickly through the wood and to step easily over downed trees while predators pursuing them must leap or go around.
E. moose has long legs that enable it to move quickly through the wood, stepping easily over downed trees while predators pursuing it must leap over or go around them.

正确答案是e，当然从it和them的单复数可以排除b c d,但是我不明白stepping easily over downed trees while predators pursuing it must leap over or go around them.怎么理解。

emmahiggins09

comma stepping 表示相对主要动作 move quickly through the wood 同时发生的伴随性动作

while predators (pursuing it) 这里括号里的是修饰predators 补充说明了这些predators 是在追逐moose 的. 所以看句子的时候可以跳过去直接看成 while predators must leap or go around them (= downed trees)

Ondksan

emmahiggins09 发表于 2017-8-27 03:31
comma stepping 表示相对主要动作 move quickly through the wood 同时发生的伴随性动作

while predators  ...

谢谢nn。所以stepping应该被看成是一个伴随状态，但是这个comma＋ving怎么能用while跟后面的句子连起来呢？这是我不明白的地方

emmahiggins09

Ondksan 发表于 2017-8-27 12:11
谢谢nn。所以stepping应该被看成是一个伴随状态，但是这个comma＋ving怎么能用while跟后面的句子连起来呢 ...

这里的 comma ving 是个修饰的成分，修饰comma 前面的主句部分。

主句 + comma ving 修饰主句 + while 从句部分，看句子的时候在理解了comma ving 是修饰的时候可以跳过去将句子简化成为主干部分：主句+while从句 这个就是很寻常的从句了，很容易就看明白了

lyy_chasedream

求问一下如果前面的主语是moose’s long legs后面就不能用it来指代所有格中的moose?

GMAT770!!

lyy_chasedream 发表于 2017-9-24 22:14
求问一下如果前面的主语是moose’s long legs后面就不能用it来指代所有格中的moose? ...

是滴，只能用its来指代

Enzoluo

这道题A为什么错了？
不能用but转折吗？
E中的while是表示转折还是时间状语从句 当。。。呢？

Ondksan

Enzoluo 发表于 2017-12-13 11:57
这道题A为什么错了？
不能用but转折吗？
E中的while是表示转折还是时间状语从句 当。。。呢？ ...

我后来再看了一下发现a还是不对的。首先a中的it指代对象有问题，it指代单数名词的话往前找只能看到一个leg，而it指代的时候还包括该名词的modifier，所以it再这里值得是moose's leg，显然不对。其次在这里用but也不合适，因为如果用but的话“but predator pursuing....“这句话就应该是跟主句，也就是"the north american..."表转折关系。在这里我觉得真正表转折的是"predator pursuing...."和“stepping over downed trees"，因为"predator pursuing...."中的them指代的应该是trees。所以e的用法更好。个人看法，有错请纠正。

Shuriiiii

Ondksan 发表于 2017-12-13 13:56
我后来再看了一下发现a还是不对的。首先a中的it指代对象有问题，it指代单数名词的话往前找只能看到一个le ...

同意！               

Janny2018

The biggest difference between (B) and (A) is the plural pronoun “their” in (B). And that’s a problem: “their” is plural, so it has to refer to either “the freshwater snails” or “the parasite’s hosts” – and those are the same thing, anyway. So that gives us: “… the freshwater snails that are the parasite’s hosts in part of [the freshwater snails’] life cycle.”

That’s not WRONG, exactly, if you’re willing to assume that the sentence is trying to explain what happens during the snails’ life cycle. But I think that misses the point: schistosomiasis is the grammatical subject of the sentence, and the sentence is clearly trying to explain why the disease has become more common. So presumably, the sentence is interested in explaining that the snails are hosts during part of the parasite’s life cycle. The snail’s life cycle really isn’t of interest to us, and wouldn’t help explain why the parasite has become more common.

So that’s miserably subtle, but it’s basically all we’ve got, unless you want to make an unnecessarily big deal out of the prepositions. (A) is better than (B), so we can eliminate (B).