紧急!完全弄不清楚英语代词、替代词的求解释!

one,前面无其它限定语时,替代“同类事物中的（不同的）一个”：
e.g.She has an English book and I have one,too.= ...and I have an English book,too.
the ...one,很少用,不够明确,一般要明确的限定语：the red/ small/ black/ larger + one,etc.
加了合适的限定语后：特指.也指同类事物中的特定的一个,避免重复前面提到的名词.
Of the three apples,I want the smallest/largest one =apple.避免再说：the smallest apple.
that
1.替代前面提到的相同的不可数名词：
The weather in Beijing is colder than that (= the weather) in Shanghai in winter.
2.替代单数可数名词,功能= it,指同一个事物,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.指代前面描述的整个事件或情形.
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,永远不可以做替代词!
those (things/ people),= the ones,指代同类事物或人群中的另一群/组,复数：
The students in Class 1 are more hardworking than those in Class 2.
those = the students in Class 2.都是学生,但是不同班级的学生.
The books in this shop are cheaper than those (books) in that shop.
those = the books in that shop.都是书,但是不同的书.