问题补充：
Jane is a nurse in the hospital, she learned in a local medical school.
A. after that
B. after which
C. before that
D. before which
答案：
A. after that
B. after which
C. before that
(答案→)D. before which
解析：根据题意,简是一家医院的护士,在那之前她在本地一家医学院学习.后面关系代词指代前面整句话内容,非限制性定语从句所修饰的不是某一个词，而是整个主句或是主句中的一个部分，这时一般采用which来引导。故选D.
