A other 是指别的,如other people.
B the other,一般是这么用的,one...the other.
eg.There are two girls in the classroom,one is reading books,the other is sleeping.
C another 是指“另一个”,就是题目这么用的,I have eaten an apple,but I want another one.
D the others 是指“其他”,
eg.Jone is playing basketball,the others are watching.