ones:n（名词）. 其中之一（个）
例句： We were the only ones excited.我们是唯一的兴奋。(主要泛指多个物体中的一个)
These apple are bigger than those ones.（ones=apples）These shoes are too small.Please get met some larger ones.(ones=shoes)
I have a new coat and several old ones.These yellow waistcoats are so small. I want those green ...
these：是泛指多个事物(也可以代指事情而ones一般不代指事情)，另外those还可以做形容词，ones则不行
These are my books.
These books are mine.
