He ___a lot of time explaining the reason___the people A spent,to B took,to C spent,for D took,fort

题目

He ___a lot of time explaining the reason___the people A spent,to B took,to C spent,for D took,fort
我知道是用spent,但是后面的就不清楚,,还是用for

答案

只能用to,这是固定搭配.请看例句：
Never explain yourself to any one.
不用为自己做任何解释.
Please explain this problem to me.
请将此问题解释给我听.