Overthepasthalfcentury,usingchemicalfertilizers
問題詳情:
Over the past half century, using chemical fertilizers _____ very common in farming.
A. had become B. became C. has become D. becomes
【回答】
C
知識點:現在完成時及其被動式
題型:選擇題
問題詳情:
Over the past half century, using chemical fertilizers _____ very common in farming.
A. had become B. became C. has become D. becomes
【回答】
C
知識點:現在完成時及其被動式
題型:選擇題