101. Professor Smith and Professor Brown will _____ in giving the class lectures.
A. exchange B. alter C. shift D. alternate
[答案]D. alternate.
[注释]alternate vt./vi. 轮流，交替发生或出现：Wet days alternate with fine days.(晴雨天交替更迭。)The weather today will alternate between fine and cloudy.(今天的天气将是晴间多云。)shift般动，移动（vt.）；转移到，迁移（vi.）；改变：1)Lend me a hand to shift the piano, will you?(请帮个忙搬一下这台钢琴。) 2)They have shifted away from this area.(他们已从这一地区迁走了。) 3)The candidate is constantly shifting his opinion about the problem.(这位竞选者在这个问题上不断改变他的观点。)exchange交换；exchange... for ... 用.......换......；alter(部分)修改。
