问题
选择题
Professor James will give us a lecture on the Western culture, but when and where _______ yet.
A．hasn’t been decided
B．haven’t decided
C．isn’t being decided
D．aren’t decided
答案
答案：A
考查时态及主谓一致。主语when and where作主语，谓语动词用单数，根据yet可知为现在完成时，选A。
