They analyzed bacteria, fungi, parasites and chemicals.

他们分析了细菌、真菌、寄生虫和化学质。

Asthma attacks can be triggered by pollen, dust, harsh chemicals or scents.

花粉、灰尘、刺激性化学质或气味可引发哮喘。

Cigarette smoke contains 69 chemicals that are known to cause cancer.

香烟含有69种致癌化学质。

It also generates reactive chemicals that attack the microbes from within.

它还能产生活性化学质，这种化学质能从内部攻击微生。

There are two important chemicals found in all our brains - dopamine and acetylcholine.

多巴胺和乙酰胆碱。

For bioluminescence, creatures require two unique chemicals.

为了生发光，生需要两种独特的化学质。

Now, how did you discover these chemicals?

你们怎样发现化学品？

Never use harsh chemicals that can discolor the boot.

千万不要使用强效化学质，以免靴子褪色。

It was easy to get the chemicals, but he needed the bodies.

添加剂很容易得到，但没有测试者。

Industries pollute rivers by dumping poisonous chemicals into them.

工业企业向河流倾倒的有毒化学质，污染了水源。

A train derailment earlier this month spilled toxic chemicals.

本早些时候，一列火车脱轨，泄漏了有毒化学质。

What's the plants' motivation for producing such chemicals?

那制造这样一种化学质何缘由呢?

Exercise releases endorphins which are natural feel-good chemicals in the body.

运动可以释放内啡肽，这一种让人感觉良好的天然化学质。

Scientists believe there might be such chemicals lying at the bottom of Europa's ocean.

科学家认为木卫二地表下的海床上一定存在这些化学质。

These ozone-destroying chemicals are used in aerosol sprays on Earth.

这种能够破坏臭氧层的化学质在地球上用于气雾喷雾器。

The light emitted by your devices releases wakeful chemicals in your brain.

设备的屏幕光会在大脑中释放出让人清醒的化学质。

If we mix these two chemicals together, they will form an acid.

如果我们把这两种化学混在一起，他们会形成酸。

In the fields, farmers use too many chemicals which destroy the soil.

农民在田地里用了太多化学品，破坏了土壤。

I sent Poole to the same chemist to fetch some more chemicals.

我派普尔去同个药剂师那里取药。

And it finds these chemicals at very low levels, usually parts per billion.

它发现的这些化学质含量很低，通常十亿分之一。