为什么冬天会呼出「白雾」? Why Can You See Your Breath When It’s Cold Out?
Why Can You See Your Breath When It’s Cold Out?
作者 Nick Kembel
本图文出处:
https://www.ivy.com.tw/newsLetter/an...080116401052110MP3:
https://www.dropbox.com/s/nxz8uoqje0rugz1/%E7%82%BA%E4%BB%80%E9%BA%BC%E5%86%AC%E5%...8C%E7%99%BD%E9%9C%A7%E3%80%8D.rar?dl=0为什么冬天会呼出「白雾」? Why Can You See Your Breath When It’s Cold Out?
空气中的湿度愈高，你呼出的气就愈能被看见。
目录 / More to Learn / 中文翻译(& 答案)
科普园地
Have you ever been in such cold weather that you could see your breath? Did you feel as though you were a mythical creature emitting a cloud of mist each time you breathed out? Well, sorry to ruin your fantasy, but there’s a scientific explanation for this fascinating phenomenon.
As you probably already know, every time you inhale, your lungs absorb oxygen from the air. When you exhale, your lungs put carbon dioxide (CO2) back into the air. The warm air released from your body with each exhalation contains vapor because of the moisture from your lungs, throat, and mouth. The warmth gives the particles of water the energy they need to keep moving rapidly. But when the air outside is cold, the water particles slow down and move closer together, forming little drops of water in the air, which is a process referred to as condensation. These drops of water suspended in the air appear like a cloud under lights, which is why you are able to see them.
How cold does it need to be for you to witness this phenomenon? Actually, there’s no set answer. It depends on other factors, such as the humidity level of the air—the more humid the air, the more visible your breath will be. But generally speaking, you can usually see your breath when the temperature reaches around 7°C or cooler. One tip to see it more easily is to open your mouth wide and exhale from deeper in your throat so that the air coming out will be warmer and carry more vapor.
So, the next time the mercury in the thermometer plummets, step outside, take a deep breath, exhale, and enjoy the spectacle!
1. Which of the following words in the passage means “the transformation of a gas into a liquid”?
(A) Spectacle.
(B) Exhalation.
(C) Phenomenon.
(D) Condensation.
2. Which of the following statements is true about the air exhaled from the human body?
(A) It stops moving if the temperature is too low.
(B) It contains a large amount of oxygen.
(C) It is a gas and normally not visible.
(D) It is completely dry and warm.
3. According to the passage, under which circumstances will you be less likely to see your breath?
(A) Breathing out air on a freezing rainy day.
(B) Releasing your breath when the weather is chilly.
(C) Blowing out your breath when the temperature is below 0°C.
(D) Taking a deep breath under the sunlight and expelling it from the nose.
答案：1.D 2.C 3.D
单字片语整理
Words in Use
●
particle [ˋpɑrtɪk!]
n. 微粒；粒子
●
suspend [səˋspɛnd]
vt. 中断，中止；吊销（执照）；垂挂，悬挂
●
absorb [əbˋsɔrb]
vt. 吸收；理解
●
witness [ˋwɪtnɪs]
n. 证人
vt. 目击
●
humidity [hjuˋmɪdətɪ]
n. 湿气，湿度
●
transformation [͵trænsfɚˋmeʃən]
n. 变形，转型
●
vapor [ˋvepɚ]
n. . 蒸气
●
thermometer [θɚˋmɑmətɚ]
n. . 温度计
●
spectacle [ˋspɛktək!]
n. . 奇观
●
mythical [ˋmɪθɪkəl]
a. 神话的；虚构的
●
emit [ɪˋmɪt]
vt. 发出，散发
●
exhalation [͵ɛksəˋleʃən]
n. 呼出
●
condensation [͵kɑndɛnˋseʃən]
n. 凝结
●
mercury [ˋmɝkjərɪ]
n. 水银
●
expel [ɪkˋspɛl]
vt. （从体内或容器内）排出
●
plummet [ˋplʌmɪt]
vi. 骤降，暴跌
Practical Phrases
●
generally speaking 一般而言
= in general
●
carbon dioxide 二氧化碳
Plants absorb carbon dioxide and produce oxygen.
植物吸收二氧化碳并且制造氧气。
●
take a deep breath 深呼吸
I always take a deep breath before going on the stage.
我每次上台前都会深呼吸。
●
be referred to as... 被称作⋯⋯
The president of the US is sometimes referred to as the chief executive.
美国总统有时被称作最高行政首长。
●
as though + S + V 好像／仿佛⋯⋯
Tina acts as though she’s tough. In fact, she
is quite timid.
蒂娜表现得好像她很强悍。其实，她胆小如鼠。
More to Learn
breathe [ brið ] vi. 呼吸
breathe out 呼气
breathe in 吸气
• The beginner practices how to breathe under water using scuba equipment.
那位初学者练习如何在水下使用浮潜设备呼吸。
以下介绍其他与「呼吸，呼气」相关的动词用法:
a. inhale [ ɪnˋhel ] vi. & vt. 吸入
exhale [ ɛksˋhel ] vi. & vt. 呼出(空气)
• If you inhale those toxic fumes, you will get sick.
如果吸进那些毒气，你就会生病。
• Before the match, the player took a deep breath and exhaled to ease his nervousness.
在比赛前，该选手深呼吸然后吐气来缓解紧张。
b. respire [ rɪˋspaɪr ] vi. 呼吸(正式用法)
• To be able to respire underwater, humans need special equipment.
为了能在水下呼吸，人类需要特殊的设备。
c. gasp [ gæsp ] vi. (因惊讶、害怕、疼痛等而)倒抽一口气/喘息
• I gasped with pain when the nurse gave me a shot.
护士帮我打针时，我痛得倒吸一口气。
d. pant [ pant ] vi.(因吃力而)气喘吁吁
• Eddie could not help panting after climbing five floors to the office.
艾迪爬了五层楼到办公室后累得气喘吁吁。
中文翻译(& 答案)
为什么冬天会呼出「 白雾」?
你曾身处在冷到可以看见自己呼出的气的寒冷天气下 吗?每次呼气的时候，你是不是觉得自己好像是一只吐出薄 雾的神兽?嗯，很抱歉破坏你的幻想，但这有趣的现象是有 科学解释的。
正如你可能已经知道的，每次你吸气，你的肺就会从空 气中吸收氧气。当你吐气时，你的肺会将二氧化碳排回空气 中。因为肺部、喉咙和嘴巴有水分，所以随着每次呼吸从身 体释放出的暖气都含有水蒸气。气体的温度给予水粒子所需 的能量持续快速移动。但当外面的空气是冷的，水粒子会慢下来并向彼此更靠近，在空气中形成小水滴，这个过程被称 为凝结。这些悬浮在空气中的小水滴在光线下看起来像一团 云，这就是为什么你能看得见它们。
那要多冷你才看得见这个现象呢?其实，并没有固定的 答案。其取决于其他因素，像是空气中的湿度 ─ 空气中 的湿度愈高，你呼出的气就愈能被看见。但一般来说，通常 当气温达到约摄氏七度或更冷时，你便能看到你的气息。想 要更容易看到气息的一个小诀窍，就是张大嘴巴并从喉咙的 更深处吐气，如此一来吐出的气会更暖并挟带更多水蒸气。
所以，下次温度计里的水银骤降时，走出户外、深呼 吸、吐气，然后欣赏眼前的奇观吧!
1. 下列哪一个文中的单字意思是 “the transformation of a gas into a liquid”?
(A) 奇观。
(B) 呼气。
(C) 现象。
(D) 凝结。
2. 关于人体吐出的气体，下列叙述何者正确?
(A) 如果气温太低，它会停止移动。
(B) 它含有大量的氧气。
(C) 它是气体且通常看不见。
(D) 它是完全干燥且温暖的。
3. 根据本文，在何种情况下你较不可能看到自己的气息?
(A) 在寒冷的下雨天吐气。
(B) 在冷飕飕的天气下吐气。
(C) 在温度低于摄氏零度时吐气。
(D) 在阳光下深呼吸并从鼻子吐气。
题解: 根据本文第三段，湿度高、气温低于摄氏七度时 便能看到气息，若要更容易看到，需从「喉咙」 的更深处吐气，以挟带更多水蒸气，可知 (D) 的 情况下较不可能看到吐出的气，故选之。
