Their problem today is somewhat similar to they faced many years ago.A. thatB. whichC. th

问题补充：

Their problem today is somewhat similar to they faced many years ago.

A. that

B. which

C. that which

D. it

答案：

A. that

B. which

(答案→)C. that which

D. it

解析：考查定语从句。定语从句缺少先行词，这里用that代指Their problem，用了that之后，为避免引起歧义，不能再用that引导定语从句，故用which。故选C。