主语从句it，what，that的区别。以此为例 显然，孩子要什么家长买什么会宠坏他们的。（obviously）

如果用it：It is obiously that parents buy whatever their children want will spoil them.
如果用what:What is obiously is that parents buy whatever their children want will spoil them.
如果用that：That parents buy whatever their children want will spoil them is obiously .
这几种都翻得对吗？这三个在翻译句子时该怎么选啊？蛋疼

都对，举个例子给你看：That the earth goes around the sun is known.=It is known to all is that the earth goes around the sun. that 引导的主语从句常用it 代替，即形式主语句型。
（What is known to all） is（ that the earth goed around the sun）.这句用了一个主语从句和一个表语从句。还可以说：As is known to all, the earth goed around the sun.不过这是as 引导的定语从句。

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