分为的英文：
fall into ;split into

参考例句：

A biographical trilogy
分为三部的传记

The right vagus divides into celiac and gastric branches
右干分为腹腔和胃支。

Sounds are classified into two kinds: sonic and ultrasonic.
声波分为两类，即普通声波与超声波。

The shuttle looms have a wide degree of versatility and fall into three main classes.
有梭织机是多种多样的，它可分为三类。

He has subdivided it into four units.
他已经将它分为四个单元。

The rocks of the Critical Zone can be grouped into two petrologic series
关键带的岩石可以分为两个岩组。

Overhead variances may be usefully considered as variable overhead variances and fixed overhead variances.
我们可以把管理费用分为可变费用和固定费用两种。

Atoms can be subdivided into neutrons, protons and electrons.
原子可以再分为中子、质子和电子。

anatomically, the nervous system is divided into the central nervous system and the peripheral nervous system
解剖学上把神经组织分为中枢神经系统和周围神经系统。

I topped out at 85 out of 100 on the test.
我在100分为满分的考试中取得了85分。

fall是什么意思：
v. 落下；倒塌；摔倒；下降；减弱；阵亡
n. 摔倒；下降；秋天；垮台；陷落；瀑布
adj. 秋天的

Sleet is falling.
天上下起了冰雹。

fall into disfavour
失宠失众望

We observed the barometer fall. [The barometer was observed to fall.]
我们看见晴雨表下降。

into是什么意思：
prep. 进入…中；进入…状态；持续到；输入
split是什么意思：
v. （使）裂开，分离；分担，分享；分割；（使）分裂；离开；揭发；增加发行
n. 裂缝；意见分歧；不同；一份；劈腿
adj. 裂开的；分裂的

They didn't crystallize, they split.
他们不是具体化，而是分裂。

The issue will split the Demoratic Party.
该问题会分裂民主党的。

Your coat has split at the seams.
你的上装接缝处裂开了。