one,前面無其它限定語時,替代“同類事物中的（不同的）一個”：
e.g.She has an English book and I have one,too.= ...and I have an English book,too.
the ...one,很少用,不夠明確,一般要明確的限定語：the red/ small/ black/ larger + one,etc.
加了合適的限定語后：特指.也指同類事物中的特定的一個,避免重復(fù)前面提到的名詞.
Of the three apples,I want the smallest/largest one =apple.避免再說：the smallest apple.
that
1.替代前面提到的相同的不可數(shù)名詞：
The weather in Beijing is colder than that (= the weather) in Shanghai in winter.
2.替代單數(shù)可數(shù)名詞,功能= it,指同一個事物,即前后所指是“原物”.
I lost my English dictionary some days ago.I still haven't found it/ that= the dictionary.
3.指代前面描述的整個事件或情形.
Steve Jobs passed away too early.That/ It maked Apple fans extremely sad.
that/it = the situation that Steve Jobs passed away too early.
these,永遠不可以做替代詞!
those (things/ people),= the ones,指代同類事物或人群中的另一群/組,復(fù)數(shù)：
The students in Class 1 are more hardworking than those in Class 2.
those = the students in Class 2.都是學(xué)生,但是不同班級的學(xué)生.
The books in this shop are cheaper than those (books) in that shop.
those = the books in that shop.都是書,但是不同的書.