1. act. Vt.扮演（……角色）；假装,装作

Who's acting (= taking the part of) Hamlet?

谁演哈姆雷特？

The actor acts the part of the hero.

这位演员扮演主人公。

He has acted(the part of Romeo)in many theatres.

他已在许多剧场里演出过(扮演过罗密欧)。

In the play ' A Merchant of Venice’ he acts the part of Shylock.

在戏剧《威尼斯商人》中，他扮演夏洛克一角。

He's been acting the devoted husband all day.

他整天装作模范丈夫的样子。

I decided to act dumb.

我决定装哑。

Chris acted astonished as he examined the note.

克里斯检查记录时故作震惊状。

2. act on（对…）有作用，有影响；根据（建议、信息等）行事

Alcohol acts quickly on the brain.

酒精对大脑迅速产生影响。

Acting on information from a member of the public, the police raided the club.

警察根据一个老百姓的报告，突然搜查了这家俱乐部。

Why didn't you act on her suggestion?

你为什么没有按照她的建议去做呢？

A patient will usually listen to the doctor's advice and act on it.

患者通常都会遵照医嘱行事。

3. act as担任……职务；起……的作用

I don't understand their language; you'll have to act as interpreter,

我不懂他们的语言,你得当翻译。

He acts as head of the department when his boss is away.

老板不在的时候,部门由他领导。

Can you act as interpreter?

你能担任口译吗？

He acted both as the ship's surgeon and as chaplain for the men.

他在船上为水手们兼作外科医生和牧师。

hormones in the brain that act like natural painkillers

大脑中起着天然止痛药作用的激素

Classroom testing, if well done, most certainly acts as a stimulus to study and real learning.

课堂测试，如果做得好，肯定会刺激学习和真正学有所成。

stimulus /ˈstɪmjələs/

n.(使生物产生反应的)刺激；刺激物；促进因素；激励因素

复数：stimuli

stimulus (to/for sth) | ~ (to do sth)

Books provide children with ideas and a stimulus for play.

书不仅给孩子们以思想，而且使他们玩得更有意思。

The new tax laws should act as a stimulus to exports.

新税法应该能促进出口。

Poverty is a stimulus to industry.

贫穷能使人勤劳。

Regard each failure as a stimulus to further efforts.

把每次失利看成对进一步努力的激励。

Interest rates could fall soon and be a stimulus to the US economy...

利率可能很快就会下调，从而刺激美国经济。

In the claustrophobia of her parents' house she had no stimulus for creativity.

在父母那所令人感到封闭恐惧的房子里，没有任何东西可以刺激她的创作。

Books provide children with ideas and a stimulus for play.

书不仅给孩子们以思想，而且使他们玩得更有意思。