It is cheaper to throw them away than _________ them.

It is cheaper to throw them away than _________ them.
A、to repair
B、repairing
C、to have repaired
D、repairs
【正确答案】：A
【题目解析】：it is cheaper to do sth. than to do sth.做...比做...更便宜
句意：把它们扔掉比修理它们要便宜。