OG13 SC97 求教关于some time的一些

willgoeu

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~!!

reginechen

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“。

willgoeu

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。。。

reginechen

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

willgoeu

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~~

reginechen

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...

willgoeu

谢谢楼上，好厉害！