问题补充：
—Shall I wait here for three hours?
—Yes. Three hours for you to wait for such a doctor.
A. are not very long
B. is not long enough
C. was not long enough
D. will be too long
答案：
A. are not very long
(答案→)B. is not long enough
C. was not long enough
D. will be too long
解析：句意：--我要在这里等3个小时吗？--是的，等医生三个小时对你来说不够长。主语是时间three hours，谓语用单数，而且enough修饰形容词long，所以选B。
