问题补充：
Last winter, many places of southern China were struck by heavy snowstorms, more than 120 people were killed.
A. from which
B. for which
C. at which
D. in which
答案：
A. from which
B. for which
C. at which
(答案→)D. in which
解析：句意是：去年，中国南方的很多地方被暴风雨袭击，在暴风雨中120人丧生。介词+which，介词的选择可以根据先行词来决定，或者由后面的定语从句的动词搭配决定，这句话的先行词是heavy snowstorms用in which指in heavy snowstorms，选D。
