Don't you know that Australia was as a matter of fact（ ）used to be a nation of prisoners?A.where B.what C.that D.whichwhere为什么不可以,这个不是主语从句吗?我知道是缺少主语，where难道不能当主语吗？

Don't you know that Australia was as a matter of fact（ ）used to be a nation of prisoners?A.where B.what C.that D.whichwhere为什么不可以,这个不是主语从句吗?我知道是缺少主语，where难道不能当主语吗？
Don't you know that Australia was as a matter of fact（ ）used to be a nation of prisoners?
A.where B.what C.that D.which
where为什么不可以,这个不是主语从句吗?
我知道是缺少主语，where难道不能当主语吗？

Don't you know that Australia was as a matter of fact（ ）used to be a nation of prisoners?A.where B.what C.that D.whichwhere为什么不可以,这个不是主语从句吗?我知道是缺少主语，where难道不能当主语吗？
"as a matter of fact" 是插入语,删去不看.故题中从句是跟在"was"后面的,属于表语从句.where不能引导表语从句,也不能在从句中作主语.what,that,which都能引导表从,你也知道从句少主语,若用that则与前面"that" 重复,若用which应该有一个范围（例如：...which is the best）,只有what即可引导表从,又无范围限定.

was后的表语从句
used前少主语

看意思 怎么怎么样澳大利亚 不是地方 老大

where是副词，不能作主语。

表语从句，从句欠主语，名词性从句只要是欠主宾表都用what
where 叫做状语，句子结构完整你才考虑where

因为（）的句子缺少的是主语 只能用what回答