——Have you finished the plan？ ——Yes, and it_____ by the experts for three times.( )
A.was being studied
B.has studied
C.has been studied
D.studied
正确答案是C
——Have you finished the plan？ ——Yes, and it_____ by the experts for three times.( )
A.was being studied
B.has studied
C.has been studied
D.studied
正确答案是C