No causative studies has ever shown artificial sweeteners causing weight gain.

没有任何研究表明人造甜味剂会导致体重增加。

However, in about 40% to 25% of the cases the causative genes are still unknown.

但是，有40％至25％病例的致病基因仍然未知。

Maybe you noticed this structure is called the causative.

也许你注意到这结构称为使役。

The causative verb or the other verb?

使役词还是另词？

There are more than 10 causative verbs in English.

英语中有 10 多使役词。

Treatment of precancerous lesions begins with active surveillance, removing any diseased tissue, and stopping any causative agents, like smoking and alcohol abuse.

前病变的治疗要从积极监测开始，任何病变组织都要，还要停止接触切致物，如戒烟戒酒。

In Africa, we experience more than 140 outbreaks every year: viral outbreaks, bacterial outbreaks, or outbreaks of unknown causative agent.

在非洲，我们每年经历 140 多起疫情：病毒疫情、细菌疫情或未知病原体疫情。

This causative verb is used to say that we forced someone or something to do something.

这使役词用来说我们强迫某人或某事做某事。

It's about the causative verbs 'have' and 'get'.

内容关于使役词 have 和 get。

That means that more than one carcinogen, or causative factor, is needed to cause the disease - like abusing alcohol and using tobacco.

意为不止种致物，或诱发性因素，在致病过程中协同作用，像是酗酒以及烟草的使用。

When we use let as a causative verb, it means that we allow someone to do something.

当我们使用 let 作为使役词时，这意味着我们允许某人做某事。

Again you only need to conjugate the causative verb.

同样地，你只需要改变使役词的形式。

Let's look at another causative verb — have.

我们来看看另使役词 have。

Right, let's get started with the causative verbs.

好的，我们开始讲解使役词。

There are lots of causative verbs and 'make', 'let' and 'have' are the most common ones.

使役词有很多，“make”、“let”和“have”是最常见的。

As I said before, we're looking at five verbs that we use with causative structures.

就像我之前说的那样，我们要学习五使用使役结构的词。

There's the causative verb, then the person who does the action, and then the action.

首先是使役词，然后是做作的人，最后是作。

Last week we looked at the meanings of three common causative verbs.

上周我们学习了三常见使役词的意思。

We are going to be talking about causative verbs, in particular, have, make, get, help and let.

我们将讨论释义词，特别是 have，make，get，help 和 let。

The tricky thing is the pattern they follow when they're causative verbs, and it's this.

棘手的是，当它们是使役词时，所遵循的模式是这样。