1._____is really hard_____them to climb mount tai A.this,to B.it,for C.this,for D.it,to
问题描述：
1._____is really hard_____them to climb mount tai A.this,to B.it,for C.this,for D.it,to
需要理由
答
.__It___is really hard__for___them to climb mount tai
答案选B,it is hard for sb to do ,对某人来说做某事很难是固定搭配