It is such an interesting book THAT we all like it.It is such an interestingIt is such an interesting book THAT we all like it.It is such an interesting book AS we all like 什么时候用as什么时候用that

such ... that ... 中的that不做后面句子的成分
所以that后面要是一个完整的句子

但是as在后面的句子中是做宾语
也就是说we all like不是一个完整句子

如果满意，请采纳~ 谢谢！

such...as用于引导定语从句，such...that 用于引导结果状语从句。如：
I’ve never heard such stories as he tells. 我从未听过他讲那样的故事。
It was such a cold day that there was nobody on the street. 天气很冷，街上没有一个人。
试比较：
He is such a good teacher as we all respect. 他是一位我们大家都尊敬的好老师。(as引导的是定语从句，as 在该定语从句中用作respect的宾语)
He is such a good teacher that we all respect him. 他是那样一位好老师,以致于我们大家都尊敬他。(that 引导的是结果状语从句，that在该状语从句中不充当句子成分，另外注意句中的respect带有宾语him)

从句中有主谓宾用that,从句中只有主谓没有宾语,这时候要用AS指代宾语