whichone的意思是哪一个哪个哪辆。例如Which one do you like best? 你最喜欢哪一个Show me which one you like and I'll buy it for you.
which ones的意思是哪几个。例如：Point out to me which ones you like best? 指给我看，你最喜欢哪几个There are many books on the floor. which ones are yours.
