标题: GMAT 真题21－３４ [打印本页] 作者: Allen 时间: 2003-12-10 12:55 标题: GMAT 真题21－３４ 34. 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.
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
我选Ｅ, but un-official answer in the test is A.请大虾指教作者: ios 时间: 2003-12-10 15:50
这题我也错了。 e的逻辑意思有问题，were表示以前认为，现在不这么认为。作者: lizaz 时间: 2003-12-10 17:24
date 是一个具体的时间点，后面要跟when