人的行为常受其所处环境的约束.用英语怎么说？

人的行为常受其所处环境的约束.

A person's behavior is often regulated by his circumstances.

behavior

n. 行为，态度，（机器等的）运转状态，（事物的）反应；

例句
Ian's rages and aberrant behavior worsened.
伊恩的怒气越来越大，反常行为也愈发恶劣。

is

vt.& vi. 是（be的三单形式；n. 存在；

例句
Bollinger 'RD' is a rare, highly prized wine.
博林格RD香槟是一种名贵的备受推崇的葡萄酒。

often

adv. 常常，经常，时常，再三；

例句
Genetic abnormalities are more often associated with faults in paternal DNA than in maternal DNA.
相对于母本DNA,基因畸变往往更多地与父本DNA上的缺陷相关。

regulated

v. 控制( regulate的过去式和过去分词 )，管理，调整，调节；

例句
The admissibility of functions is regulated by continuity requirements and boundary conditions.
函数的容许性由连续性要求和边界条件来约束.

by

prep. 在…旁边，表示方式，由于，经过；adv. 经过，表示保留或保存时用，短暂拜访；

例句
...expensive make-up that we saw being advertised by a beautiful model...
我们所见的由一位漂亮模特代言的昂贵化妆品

his

pron. (he的所有格)他的，(he的物主代词)他的东西；det. 属于他的，用于名词前，自己的，指某人的，上帝的；

例句
He claimed that his parents had abandoned him...
他声称父母遗弃了他。

circumstances

n. 境况，境遇，（尤指）经济状况，命运，环境( circumstance的名词复数 )，事件，境遇，机遇；

例句
The strategy was too dangerous in the explosive circumstances of the times...
在当时那种一触即发的形势下，采取那样的策略太危险了。