date不是应该搭配at的嘛？

sportmann

我的意思是A选项it的用法有很大的歧义。it在这里做形式主语，主语本身是后面的that humans made stone tools。

所以 the earliest date when it is known that humans made stone tools 可以理解成the earliest date when that humans made stone tools is known. 这样显然是不make sense的。这个when从句里面表达的fact修饰前面的earliest date, 但这个fact并不是was known at the date.

这里要表达的是the toolmaking happened at that date, but the fact is known now.

a 选项it 指代that 从句 ,何以说指代不明?
这和 it is important that .....一样的! 指代不明何从谈起? 楼主这道题在哪找的? google 上搜找不到呀? it is 这种句型在这里是不是显的 awkward?  不如c 选项的那种表达简洁,而且 when 不如 at which 好,应该选c !不知道哪位牛人能给分析一下 a 选项

-- by 会员 zxtcomeo (2010/6/6 17:51:55)

puqiandi

这道题答案给的是E不知道有没有错误

Rachel76

上周发邮件询问了，答案有错！答案应该是C！

pansean

B中，had made有错，过去完成时表示过去的过去，句中没有其他过去时形式
D中，对多年前发生的事描述竟然用现在进行时，错误明显
E中，of运用有误，造成human date is a type of date的误解
剩下AC，个人觉得2个都没明显语法错误，但从concision角度考虑，C比A的形式主语更简洁。

hermit127

256. (28362-!-item-!-188;#058&003003) (T-4-Q1 TS-7-41)
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.
A. when it is known that humans made
B. at which it is known that humans had made
C. at which humans are known to have made
D. that humans are known to be making
E. of humans who were known to make

1, date from 一般用主动表达“始于。。”；
2, be dated (at) +时间， 表示**的年代定于什么时间；

另外，
1, be known for sth,
2, be known as sth,
3, be known to do sth,

这个是PREP原题，答案是C，
A,B, 里面it做形式主语引导从句，我觉得没有指代问题，但是大家发现没有when和at which这个时候变成修饰be known了，改变句意，而C里面at which是修饰have made，这一点，从C里面的are to known也可以证实。

E，里面date of humans改变原意。

请NN指正！