its/it's

its 是 it 的物主代词(即所有格)，而 it's = it is 或 it has。

It's no use

It's no use doing/It's no use to do 见 it $^{6}$

It's time + 不定式或过去时 见 It's time for us to go

It takes/took a long time to do sth. 见 take $^{2}$

It was not until. 见 until( It was not until)

item 见 news, piece/item