It would be a good idea to use a plastic bottle, cut off, as a container to grow young plants in.
A. of which the top
B. the top is
C. the top of which
D. with its top
网友回答
A. of which the top
B. the top is
C. the top of which
(答案→)D. with its top
解析：此题是独立主格结构，如果题干改为 is cut off,答案则为A或C