it的形容詞性物主代詞和名詞性物主代詞

It's about this high.

大約有這麼高。

There have been some problems but basically it's a good system.

雖然出現過一些問題，但這基本上仍不失為一個好系統。

It's been quite a day, one way and another.

從幾方面看，這是不尋常的一天。

It's good to meet people from different parts of the country.

結識來自這個國家不同地區的.人是有益的。

It's only human to want the best for your children.

為自己的孩子謀求最好的條件是人之常情。