Question

【題目】We ______ on it for many hours, but we have not yet reached any conclusion. ( )

A.are being workedB.are workingC.have been workingD.have been worked

Answer 1

【答案】C

【解析】

句意：我們已經(jīng)做了很多小時(shí)了，但我們還沒(méi)有得出任何結(jié)論。根據(jù)but后時(shí)態(tài)，可以判斷出到現(xiàn)在還沒(méi)有得出結(jié)論，有可能還要繼續(xù)下去，所以要現(xiàn)在完成進(jìn)行時(shí)。故選C。