問題詳情:
______ scientists have learned a lot about the universe, there is much we still don't know.
A. Once B. Since C. Though D. Unless
【回答】
C
考點:考查狀語從句
知識點:連詞
題型:選擇題
問題詳情:
______ scientists have learned a lot about the universe, there is much we still don't know.
A. Once B. Since C. Though D. Unless
【回答】
C
考點:考查狀語從句
知識點:連詞
題型:選擇題