天山7－Q41答案应该为A，觉得C就是不对。请教！

riverhouse

天山7－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.

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

答案是C，但是我觉得A合适。看过以前的讨论帖，不多，就一贴，说服不了我。C用完成时第一个就被我否决了。向各位请教。

riverhouse

看来没有人理我，呜555

DARRENMA

have made表示了准确的句意: 表示当时人类已经制造了工具(表制造的延续). made 表示当时以前人类制造过工具(表制造的停止).

现在完成时表过去动作延续到现在. 过去时表动作的停止.

建议LZ做语法题要根据逻辑意思判断. 逻辑意思大于一切.

[此贴子已经被作者于2005-12-10 23:42:11编辑过]

riverhouse

原句意是human known to have made stone tools.难道人类延续到现在还在制造stone tools？楼上的解释欠缺逻辑。sorry, I cannot agree with you.

DARRENMA

意思是:到当时 ( more than 150,000 years the earliest date )制造炻器这个事实已经发生了,而且制造炻器在人类历史是一个反复持续的动作,持续了一段时间(制造炻器的历史应该有几千年吧).

如果用made, 则表示一次性动作,逻辑就错了:说人类制造炻器就制造一次,以后就不用再造了,炻器就可以永远使用了,不会坏了.

本句要用过去时,应改为: bagan to make 才可以讲得通.

不知道我有没有解释清,当时我做此题时比较A和C,觉得C最好,意思表达最准确.