Professor Smith and Professor Brown will in giving the class lectures.
A. exchange
B. alter
C. shift
D. alternate
网友回答
A. exchange
B. alter
C. shift
(答案→)D. alternate
解析：考查动词词义辨析。alternate vt./vi. 轮流，交替发生或出现；shift般动，移动（vt.）；转移到，迁移（vi.）；改变；exchange交换；exchange... for ... 用.......换......；alter(部分)修改。