it 和that替代的区别

it代替前面提到的东西（单数）that 代替不可数名词或者是句子

it代替前面提到的东西（单数）
that 代替不可数名词

Your coat is very beautiful? Where did you buy it?(it 代替coat）

The population of China is larger than that of any country in the world.(that 代替population)

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