第2课

第二课

Lesson Two

我们的呼吸

Our breath

l 1.玻璃管 、集气瓶 、烧杯 、澄清的石灰水 、气球 、软尺 、火柴等。

Glass tube, collecting cylinder, beaker, clarified lime water, balloon, tape, match, etc.

我们生存需要呼吸 。呼吸意味着生命的存在 ，没有人可以在停止呼吸的情况下存活很长时间 。

We need to breathe to survive. Breathing means the existence of life. No one can survive for a long time without breathing.

l 2.屏住呼吸会怎样 ？

What happens when you hold your breath

（1）感受一下 。

Feel it.

（2）时间不能太长 ！

Time can't be too long!

l 我们吸进和呼出的气体相同吗 ？

Do we inhale and exhale the same gas?

（1）先收集呼出的气体 ……

Collect exhaled air first

（2）把点燃的火柴放入呼出的气体中 ……

Put the lighted match into the exhaled air

（3）还可以这样设计实验 。

You can also design experiments like this.

（4）我来试试 ！

I'll try!

提示

Tips

   二氧化碳能使澄清的石灰水变浑浊 。

Carbon dioxide can make clear limewater turbid.

3.呼吸器官主要有哪些 ？我们是怎样呼吸的 ？

What are the main respiratory organs? How do we breathe?

（1）人的呼吸器官主要包括鼻、咽 ……

Human respiratory organs mainly include nose, pharynx

（2）我们可以画一画吸气和呼气的路线图 。

We can draw a map of the way to inhale and exhale.

    鼻，口腔，咽喉，气管，支气管，肺

Nose, mouth, throat, trachea, bronchus, lung

（3）呼吸包括吸气和呼气两个过程 。

Breathing includes two processes: inhalation and exhalation.

资料卡

index card for files

呼吸是人体吸取氧气 ，呼出二氧化碳的过程 。消化器官吸收的养料与呼吸器官吸收的氧气在人体中作用 ，释放出生命活动所需的能量 。

Breathing is the process in which the human body absorbs oxygen and exhales carbon dioxide. Nutrients absorbed by digestive organs and oxygen absorbed by respiratory organs act in the human body and release the energy needed for life activities.

4. 如何保护我们的呼吸器官 ？

How to protect our respiratory organs

①吸烟会引发肺部病变 。

Smoking can cause lung disease.

②要注意环境卫生 。

Pay attention to environmental hygiene.

③寒冷的冬天要戴口罩 。

Wear a mask in cold winter.

④积极参加体育锻炼 。

Actively participate in physical exercise.

l 5.测一测我们的肺活量 。

Measure our vital capacity.

①肺活量测试仪

Vital capacity tester

②我吹的气球最大 ……

The balloon I blow is the biggest

l 调查吸烟和空气污染对呼吸器官的危害 ，写出调查报告 。

Investigate the harm of smoking and air pollution to respiratory organs, and write the investigation report.