Do you know that Australia was as a matter of fact

问题补充：

Do you know that Australia was as a matter of fact

答案：

首先要排除as a matter of fact 的干扰,它是个独立成分,或理解成插入语,这样句子就明了了,Australia was (as a matter of fact )what used to be a land for prisoners.what 引导一个表语从句,在从句中做主语.

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供参考答案1:

Aas a matter of fact是插入语，意思是事实上，挑出来不用管。

句子主要成分是 Australia was ———。

后边是一个定语从句，used to be 什么什么是要修饰要填的词。

这句话的意思是 澳大利亚以前是关犯人的地方。

先行词用what

类似的句子有， you have to do what is important.