问题补充：
Do you know the waste material can be made use this kind of the toy?
A. of producing
B. to produce
C. to producing
D. of to produce
答案：
A. of producing
B. to produce
C. to producing
(答案→)D. of to produce
解析：原句可改写为：we can make use of the waste material to produce this kind of the toy.将其变成被动语态为：the waste material can be made use of to produce this kind of the toy.故选D。句意：你知道这种废料是用来被制作成这种玩具的吗？
