是使用at which修饰时间好还是when更好？探讨

qqiaoer

Q41:

Scientists have dated sharp-edged flakes of stone found in the fine-grained sediments of a dry riverbed in the Afar region of Ethiopia to between 2.52 and 2.60 million years ago, pushing back by more than 150,000 years the earliest date when it is known that humans made stone tools.

 

1. when it is known that humans made
2. at which it is known that humans had made
3. at which humans are known to have made

4. that humans are known to be making
5. of humans who were known to make

错误选择C，正确为A

这个题目的考点从答案看来是考察：时态考点？

是否选择when还是使用at which是有效性错误的问题，时态才是关键？

但是日常做题目的时候大家如何理解这个考点：时间状语后面比如year,age,通常用when修饰，但是 介词+which的修饰更优，往往更清晰？

探讨一下，感谢！

weihua89

好像没听说过介词+which更优。。。关于这部分问题我倒也想听听有没有什么好的解释。

当然，我觉得c不对主要是后面的表达有问题，原意表达的是据所知，人类那个时期制造石器。it is known的用法就相当于it is said，据说。而c在说，人类为已经制造石器所知，句意改变了。

cookercai

时间习惯搭配：

the period when... a time when.... since XXXX when..... the year that.... an age in which.....

我觉得这题human are known不好吧，it is known强调句型比较好。请牛牛指点

mouve

偶觉得,at which应该是指一个具体得时间点.date at which 如果选用得话应该是指具体得那个时间点,但是题目中应该是阐述得一个时间段得事情,无法具体到哪个时间.

另外,用一般过去时而不用过去完成时偶觉得是指在"more than 150,000 years"得事情,应该使用一般过去时得.这个不是很确定,大家给指正一下吧

qqiaoer

修饰的问题，还真的有时候很晕，所以语法看来还是要从多个角度去判断

而且还是要看是不是正确性错误，我再多想想：）

谢谢各位：）

继续加油！