Ijustdon'tunderstand 國語站 題庫 1.5W 大中小設置文字大小 問題詳情: I just don't understand _________ that prevents so many Americans from being as happy as one might expect. A. why it does B. what it does C. what it is D. why it is【回答】C知識點:主語從句題型:選擇題 TAG標籤:Ijustdontunderstand #