求教：OG 97若干问题

juyifan

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,

答案给的是选B，
OG解释说A里没有that，不平行。但是为什么不可以理解为“-”的作用相当于冒号，后面的划线部分是用来修饰 “population bottleneck”的呢？
ps A里的reducing用法确实是不对的，就先不讨论啦~纠结点在于这个对于平行的要求总觉得不合理。

fogetdream

怎么没有牛牛来解答啦。 我也有这个疑问：“-”的作用相当于冒号，后面的划线部分是用来修饰 “population bottleneck”  撇开reduce错误的话，A是不是也说的过去

春雨Q

可是manhattan说破折号可以当冒号啊。。。。

joybb

juyifan 发表于 2013-5-31 22:08
嗯，我在揣摩揣摩。~

揣摩出来了吗？我也是这里不懂呢，请赐教啊！

juyifan

enkyklios 发表于 2013-5-31 21:55
我也不知道冒号啦，只是这儿这个符号是这样的
刚查了一下冒号Appositive [edit]The colon introduces an a ...

嗯，我在揣摩揣摩。~

enkyklios

juyifan 发表于 2013-5-31 21:49
多谢！不过冒号是对前面整句的解释吗？在manhattan比较上看到The rate of a reaction is affected by thr ...

我也不知道冒号啦，只是这儿这个符号是这样的
刚查了一下冒号Appositive [edit]

The colon introduces an appositive independent clause. In other words, the sentence after the colon is in appositionto the one before the colon.

Bob could not speak: He was drunk.[6]

所以不句的句子冒号的作用也不一样，本句是一个同位句，不是一个名词的演绎

juyifan

enkyklios 发表于 2013-5-31 21:29
我觉得some believe……-  如果当成一个冒号会是对前边整个句子的解释，很多人相信，和我们祖先遭受显然不 ...

多谢！不过冒号是对前面整句的解释吗？在manhattan比较上看到The rate of a reaction is affected by three factors: concentration, surface area, and temperature. 觉得这个冒号后面的东西是解释前面的一个名词的，而不是整个句子的~

enkyklios

我觉得some believe……-  如果当成一个冒号会是对前边整个句子的解释，很多人相信，和我们祖先遭受显然不是一回事，
当然如果这个句子去掉some anthropologists believe,直接从the genetic homogenelity is the result……- at some time
我觉得当成个冒号就没有问题了