問題詳情:
單項選擇。
Both his parents look sad . Maybe they _________what's happened to him .
A. knew B. have known C. must know D know
【回答】
B
知識點:動詞時態
題型:選擇題
問題詳情:
單項選擇。
Both his parents look sad . Maybe they _________what's happened to him .
A. knew B. have known C. must know D know
【回答】
B
知識點:動詞時態
題型:選擇題