1. 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
提示：本题考查时态。主语when and where与谓语动词decide之间是动宾关系, 且视为单数概念, 因此应选择使用被动语态, 排除B、D两项, 从时间状语yet看, 这里应使用完成时态, 因此答案为A项。
答案：A
