问题补充：
John is one of the staff members who to be sent abroad for further study.
A. is going
B. are going
C. have been going
D. has been going.
答案：
A. is going
(答案→)B. are going
C. have been going
D. has been going.
解析：有one of the staff members 知是其中之一，而不是唯一一个，故先行词是members ,所以谓语动词用复数。
