Tom is the only one of the students who____to Shanghai.

问题描述:

Tom is the only one of the students who____to Shanghai.
A:have gone B:have been C:has been D:had gone

这里的先行词是only one
所以是单数
所以用has been
另外,have gone 的意思是去了,还没有回来
have been 的意思是去了,已经回来了
去了上海,回来过,所以,是been
答案C