divide 与separate

divide 用于divide into 意思是把一个整体分成若干份.
separate 用于separate from 是把由个体组成的群体分成若干份.

separate:
To set or keep apart; disunite.
分隔：设置或保持隔开；使隔开
To space apart; scatter:
分散：把…分隔开；使分散：
small farms that were separated one from another by miles of open land.
小农场零星地分散在开阔的土地上
To sort:
分类：
separate mail by postal zones.
根据邮政地区分拣邮件
To differentiate or discriminate between; distinguish:
区分：在…之间区分或辨别；识别：
a researcher who separated the various ethnic components of the population sample.
区分人口样本中各种少数民族成份的研究人员
To remove from a mixture or combination; isolate.
离析：从混合物或结合体中分离；使脱离
To part (a couple), often by decree:
分离，脱离：使（一对夫妇）分离，通常通过法令：
She was separated from her husband last year.
去年她和丈夫离婚了
To terminate a contractual relationship, as military service, with; discharge.
解除：与…终止契约关系，如军队服役；解除
v.intr.（不及物动词）

divide:
To separate into parts, sect