【题目】Professor James will give us a lecture on the Western culture, but when and where ____ yet.
【选项】
A. hasn’t been decided
B. haven’t decided
C. isn’t being decided
D. aren’t decided
在线课程【答案】A
【解析】根据句意, 此处应用被动语态, 不用主动语态, 故排除B；又因为when and where表示单数意义, 故排除D；再根据句末的yet可知, 最好用现在完成时, 故选A最佳。