During the opera's most famous aria the tempo chosen by the orchestra's conductor seemed ______, without necessary relation to what had gone before.

【正确答案】 C

【答案解析】 句意：在该歌剧最为著名的咏叹调中，管弦乐队指挥所选择的拍子看起来变幻莫测，似乎与前面的节拍没有必然联系。capricious变幻莫测的，反复无常的。tedious单调乏味的，沉闷的。melodious音调优美的。cautious谨慎的，小心的。