【1】I told them （not everybody could run as fast as you did）,

可以.
it is how long that i dont know he has stayed here
再问： 第二个问题你和我想的一样，但是答案给的：I don't know how long it is that he has stayed here . 不过还是 多谢你肯回答
再答： 在这里强调句的形式是how + 形容词+ it is 因此答案是I don't know how long it is that he has stayed here . 不过我觉得其实都得可以的...
再问： how + 形容词+ it is 这个不是感叹句吗，感叹句也算强调句？
再答： 这是对强调句中特殊疑问词考法.在这种题目中要注意词序,即特殊疑问词要置于句首或在宾语从句中居首,而且这里不是单独出现how + 形容词+ it is,在这里how后面跟从句作为宾语成分,是how引导的宾语从句..不是感叹句..