問題詳情:
He was doing his homework __________ he heard the telephone ringing.
A. before B. after C. while D. when
【回答】
D
知識點:連詞
題型:選擇題
問題詳情:
He was doing his homework __________ he heard the telephone ringing.
A. before B. after C. while D. when
【回答】
D
知識點:連詞
題型:選擇題