天山-7-41

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   

I chose A, but the answer is C.

Why?

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           錯誤選項 畫線部分補充解釋date, when 為時間副詞不代特定名詞/ it 指涉不清

B. at which it is known that humans had made 錯誤選項  it 指涉不清/wordy/時態

C. at which humans are known to have made

D. that humans are known to be making         錯誤選項 to be making

E. of humans who were known to make         錯誤選項 脫節 句意怪異(推前那些做石器人類的最早日期)

I chose A, but the answer is C.

Why?

谁能解释一下吗？C为什么对啊？

现在语法区讨论的越来越少了。

我当时的理解是sbo be known to do sth是ets的fovor

虽然it is known that...通常有人们都认为...的意思,但是A的when和B的had made不OK吧.

agree.

thank you

A. when it is known that humans made           錯誤選項 畫線部分補充解釋date, when 為時間副詞不代特定名詞

B. at which it is known that humans had made wordy

C. at which humans are known to have made

D. that humans are known to be making         錯誤選項 to be making

E. of humans who were known to make    of human错

Ｃ我也解释不清，但另外四个都有明确错误，只剩Ｃ了