OG13 SC97 求教关于some time的一些

ssw920826

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 numbersB. 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,



答案给的是B，但是关于解释some time的用法还是不太懂。。。。如果表示在一段时间的话就一定要用at some time么~~
还有就是看解释貌似是说that X——that Y是平行。。我本来还以为破折号是解释的意思，就不能用平行结构的说。。。这种想法是不是错的啊TAT


多谢各位大神解答~!!

纸飞机32

xuebawannabe 发表于 2014-1-7 01:56
请教各位，所以这道题A和B的切入点在于----B的that和believe that的that平行，破折号在此表further explain ...

因为没有that,reducing的逻辑主语就变成了ancestors了，那意思就变成是ancestors reducing了their number，（自己reduce自己？）而实际上句子要表达的是ancestors遭遇了某一event，是这个event才导致数量减少。加上that，和前边的that平行，都是believe的宾语从句，句子清晰，没有歧义。这是我的理解，大家相互参考。

evysy

Some anthropologists believe that the genetic homogeneity evident in the world’s people is the result of a “population bottleneck” - (they believe) that at some time in the past our ancestors suffered an event that greatly reduced their numbers and thus our genetic variation.
anthropologists是破折号前后的主语，括号中的是可以利用平行格式省略的。但是必须加that，不加的话ancestors就变成后面的主语了。

破折号的确是解释的意思，但是并不妨碍平行。

破折号后面解释的是前面的整个 "Some anthropologists believe that the genetic homogeneity evident in the world’s people is the result of a ‘population bottleneck’"。作用是用更通俗易懂的语言来表达前面整句话。

Anthropologists believe X - (they believe) Y.

X = that the genetic...
Y = that at some time...

rorkey

笑小笑小蚂蚁 发表于 2014-9-26 21:56
亲，我觉得这个thus our genetic variation 是和前面的their
numbers 并列。and并列连词连接这两个reduce ...

终有有个人找到了问题的关键了。

关于破折号、破折号之后是否有that、sometime和at some time， from which这些都不是考点，这些表达都是正确的！！！！
问题的关键就在and thus our genetic variation，这个宾语的谓语是reduce。所以选项C和D用了被动语态，导致这个thus our genetic variation没有了谓语动词。

笑小笑小蚂蚁

兰心寒 发表于 2013-11-27 23:30
----at some time ... our ancestoers suffered an event that greatly reduced their numbers and thus  ...

亲，我觉得这个thus our genetic variation 是和前面的their
numbers 并列。and并列连词连接这两个reduced的宾语。有thus表示结果因为reduced their numbers, 所以才会reduced our genetic variation

落薇裳

chudewen 发表于 2013-4-14 12:43
如果后半句不加that的话，就会出现两句话并列而没有连词连接的情况。

Manhattan(P199): the dash is a flexible punctation mark that the GMAT occasionally employs. You can use a dash as an emphatic comma, semicolon, or colon.
In short, you cannot really go wrong with a dash!

所以dash当分号时是可以独立引导两个逻辑关系紧密但完整的句子的。所以我觉得不能因为一个dash就判断后面要加that

ssw920826

这么再看一下原题果然懂了许多~！！多谢~！

话说关于那个破折号平行的可以帮忙解释一下么~~

evysy

我想你可能是some time (两个词) 和 sometime (一个词) 有点混。

some time (两个词)= a period of time
例如用在 I've been trying to contact him for some time. 我试着联系他有一段时间了。我挺长一段时间都在试着联系他。

at some time = at an unspecific time
例如 I heard a knock on the door at some time last night. 我昨晚（不确定什么时间）听见有人敲门。
是不是和题目很像？
很久以前，（不确定什么时间）我们的祖先经历了一件事。

sometime (一个词) 也是 = at an unspecific time, 不过必须用在说未来的时候
例如 Let's grab coffee together sometime. 我们什么时候（时间暂不定）一起喝杯咖啡吧。

不知道这么解释清楚吗

evysy

两者语义不同。
Some time 表示的是“一段时间”
At some time 表示的是“在某一时间”
选谁要看句子想描述什么——在这里是“an event"，一个事件发生在”一段时间“说不过去，而是应该发生”在某一时间“。

ssw920826

多谢~其实还是有点不太明白。。。。能不能举个栗子的说。。话说看了你另一个帖子15/140的准确率让人望尘莫及的说。。。
还是说我语法真的太烂了。。。

loveberries

谢谢楼上，好厉害！

waynedgbb

受教了。

miffyhui

Some anthropologists believe that the genetic homogeneity evident in the world’s people is the result of a “population bottleneck” - (they believe) that at some time in the past our ancestors suffered an event that greatly reduced their numbers and thus our genetic variation.
anthropologists是破折号前后的主语，括号中的是可以利用平行格式省略的。但是必须加that，不加的话ancestors就变成后面的主语了。

破折号的确是解释的意思，但是并不妨碍平行。

破折号后面解释的是前面的整个 "Some anthropologists believe that the genetic homogeneity evident in the world’s people is the result of a ‘population bottleneck’"。作用是用更通俗易懂的语言来表达前面整句话。

Anthropologists believe X - (they believe) Y.

X = that the genetic...
Y = that at some time...

-- by 会员 evysy (2012/5/31 12:24:06)

NN，如果题目中出现破折号，应该如何处理呢？之前直接把它去掉，但是不是很适用...不解！

ccfish9

我想请教下：
1. 如果题目给的是——at some time in the past our ancestors suffered...（即B去掉that）是不是也可以？只做解释说明不做平行？
2. 解答中说scientists believe that X——[in other words,] that Y是平行，是that X和that Y平行吗？[in other words,]和that Y分别指的是什么内容？因为在我看来dash后面的所有都是[in other words]的内容啊。

非常感谢！