题目内容：

I suspect that each of us has tired __best to learn english well.A.our B.my C.his D.their
I suspect that each of us has tired __best to learn english well.
A.our B.my C.his D.their
为什么要选C?

优质解答

这是一个宾语从句,that后面是一个完整的句子,在each of us has tired __best to learn english well这个句子中,谓语是has,这是一个单数形式,四个答案中只有C是单数形式,所以要选C