问题补充：
We went through a period communications were very difficult in the rural areas.
A. which
B. whose
C. in which
D. with which
答案：
A. which
B. whose
(答案→)C. in which
D. with which
解析：考查定语从句：先行词是a period，定语从句中缺少in the period，用in which或where引导定语从句，句意：我们经历了一个阶段，期间在农村交流很难。选C。
