I don't think____good to copy others' homework.

A 其实有两个答案
一个是 it 或it is
这是一个模式
think加从句
it is ＋adj.＋to do
is可以省略

A 行驶宾语

C！
A B C缺谓语
更不用考虑代词用哪个了！

A
可以理解为固定用法,其实说的多了,张嘴就那么说出来了

A!!!
I don't think that it is good to copy others' homework.
宾语从句省略that和从句的谓语

C。
think后面是宾语从句，从句也应该有独立的谓语，A，B，D都没有，C的it's即it is 缩写。所以C。