求助08语法题一道!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 earl

求助08语法题一道!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 earl
求助08语法题一道!
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 madeB.at which it is known that humans had madeC.at which humans are known to have madeD.that humans are known to be makingE.of humans who were known to make求问这道题A怎么错了?

求助08语法题一道!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 earl
这道题需要一个定语从句修饰date,一般情况下我们用,the date (when/at which/that)+什么事情发生/什么人做了什么,这里中间加上"it is known that"意思上就不通顺了,因为"it is known that"这种句型本身不是一个用来改定语从句的好材料.原句的earliest最高级修饰date强调时间点,所以使用at which由于when；A,B选项逻辑意思严重违背原句意思,A,B选项的意思是humans made stone tools被it is known的时间被push back...；原句是想说human are known to have made stone tools的时间被pushing back；这就是A错误的原因 查看原帖>>