one it that those的区别和用法详解：
one, it, that和those可代替上文提过的名词，以避免重复。
它们的用法，最主要的区别如下：

it ：特指之前提到的同一个事物
（特指同物）

one：泛指之前提到的同类中的任一个人或物
（泛指同类不同物）

that：特指前文提到的同类中的特定的事物 
（特指同类不同物）

（泛指：不明确指定；特指：明确指定）

1.it：特指同物
This pencil is mine. You can have it.
这只铅笔是我的。你可以拥有它。
（it 特指上文提到的同一只铅笔。） 

 复数意义，用they/them。
These pencils are mine. You can have them.
这些铅笔是我的。你可以拥有它们。


2. one：泛指同类不同物
My pencil is broken. Can you lend me one?
我的铅笔破了。你能借给我一只（铅笔）吗？
one泛指任一只铅笔 

He couldn't find his bag. So he bought a new one.
他找不到他的书包。所以他买了一个新的。
one泛指一个书包，未明确是哪个

复数意义，用ones
I don’t like big apples. I like smaller ones.
我不喜欢大苹果。我喜欢小苹果。
ones泛指apples，未明确是哪些苹果


3.that：特指同类不同物
The weather in Hainan is better than that in Guangzhou.
海南的天气比广州的好。
that = the weather, 特指（广州的）天气

The window is bigger than that by the door.
这个窗户比门边的那个窗户大。
that= the window，特指（门边）的那个窗户 

复数意义，用those

The windows are bigger than those by the door.
这些窗户比门边的那些窗户大。
those = the windows，特指（门边）的那些窗户

TIPS:
从例句中可发现：
1）that/those 常后接修饰语，以体现特指。
比如：
The windows are bigger than those by the door.
 （特指是门旁边的那些 ）

此时：
that(指代可数名词单数) + 修饰语 = the one +修饰语
those (指代可数名词复数) + 修饰语 = the ones+修饰语

The window is bigger than that by the door.
= The window is bigger than the one by the door.

The windows are bigger than those by the door.
= The windows are bigger than the ones by the door.