问题补充:
The river are covered with trees is very long
A. which banks
B. of which banks
C. whose the banks
D. the banks of which
答案:
A. which banks
B. of which banks
C. whose the banks
(答案→)D. the banks of which
解析:句意:两岸种满了树的那条河很长。名词/代词+of+whom/which可引导非限制性定语从句,表示部分与整体的关系。C应是whose banks才对。故选D。