this question is very hard.None of us can work it out.(保持原意）this question is ______ hard for ________of us to work out
问题描述：
this question is very hard.None of us can work it out.(保持原意）
this question is ______ hard for ________of us to work out
答
this question is _too_____ hard for _____all___of us to work out too。。。to。。。结构
答
看来是too ...to 结构意思是太怎么样而不能，所以第一个空填too，从整个句子看是这个问题对于我们来说太难做不出来，是所有人，所以第二空填all。
答
too all
答
so all