The river are covered with trees is polluted.A. of which the banksB. whose banksC. the ban

问题补充：

The river are covered with trees is polluted.

A. of which the banks

B. whose banks

C. the banks of which

D. A,B,C are right

答案：

A. of which the banks

B. whose banks

C. the banks of which

(答案→)D. A,B,C are right

解析：考查定语从句关系代词的选择。关系代词代替的是先行词在定语从句中作定语。