时态语态问题Iwon’ttellthestudenttheanswertothemathproblemuntilheonitformorethananhour.vA.hasbeenworkingvB.willhaveworkedvC.willhavebeenworkingvD.hadworked要说明理由v

Question

时态语态问题
I won’t tell the student the answer to the math problem until he____on it for more than an hour.
v A.has been working
v B.will have worked
v C.will have been working
v D.had worked
要说明理由
v

Answer 1

选A,意思是,直到这个学生在这道数学题上花了超过一个小时,我才会告诉他答案.