跟读练习: How Long Can You Balance a Pencil? - 通过视频学习英语口语
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24 句
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1
Balancing a pencil or any other top -heavy object on its tip is quite a precarious task.
2
It's easy to see why top -heavy objects are unstable.
3
They just want to fall down.
4
Any little nudge will put it off balance, with gravity happy to pull its center of mass even more off balance.
5
And the more off balance it is, the more gravity pulls until...
6
Physicists call this kind of tipping an inverted pendulum, because it's kind of like an upside -down pendulum.
7
And, careful mathematical analysis of inverted pendulums will tell you the obvious.
8
They're really unstable.
9
In fact, these equations predict that
10
if a perfectly balanced pencil with a perfectly sharp tip were
11
to get nudged off -balance by just one ten -thousandth the width of an atom, it would take only three seconds to fall over.
12
There are indeed acrobats who can balance poles with other acrobats on top, and robots that can balance and catch and throw upright sticks,
13
and people who make seemingly impossible artistic rock stacks.
14
But in all these cases, keeping the objects balanced either requires an active stabilization effort, or else carefully taking advantage of the fact that the balancing point isn't actually a point.
15
So the question is this, can you balance a pencil sharpened to a perfect single atom -wide tip on its tip without active stabilization?
16
Well, to start, you'd better get rid of all the air bumping off the sides of the pencil, since the kinetic energy of a typical oxygen molecule is enough to destabilize the pencil.
17
Remember, if the pencil gets off -center by even one ten -thousandth the width of an atom, it'll fall down in under three seconds.
18
And you'd better cool the pencil and table down as close to absolute zero as you can, since the thermal jiggling of their atoms when they're hotter will similarly jiggle the pencil off -balance.
19
But even then, matter at very small scales has a spread -out, wave -like nature, which means you can't have both the pencil perfectly upright and not moving at the same time.
20
And while this quantum effect is never a real -life inhibitor of precarious pencil balancing, it means you never even could succeed.
21
However, it's still fun to see how long you can keep a pencil balanced on your fingertip.
22
The shorter the pencil, the harder it is.
23
My best time for a standard 19cm pencil was 1 .3 seconds.
24
Think you can beat it?
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本课的词汇与口语要点
这节 C1 级别的口语课以视频“How Long Can You Balance a Pencil?”为素材。 视频中反复出现的词有：pencil, balance, atom, tip, pendulum。 这段视频共有 24 个句子、413 个单词可供跟读。 讲话部分时长为 2:01。 说话人语速较快，每分钟约 204 个词，会出现较多连读和弱读。 只有 78% 的单词属于英语最常用的 3,000 词，词汇难度较高。
视频中的重点词汇
视频中最难的 15 个单词，附发音和释义：
| 单词 | 发音 | 释义 |
|---|---|---|
| pencil 名词 | /ˈpɛnsəl/ | 鉛筆 /铅笔 |
| atom 名词 | /ˈætəm/ | 原子 |
| pendulum 名词 | /ˈpɛnd͡ʒələm/ | 鐘擺 /钟摆, 擺 /摆 |
| acrobat 名词 | /ˈæk.ɹə.bæt/ | 雜技演員 /杂技演员, 馬戲演員 /马戏演员 |
| invert 动词 | /ɪnˈvɜɹt/ | 反转, 倒转 |
| precarious 形容词 | /pɹɪˈkɛəɹi.əs/ | 危險的 /危险的 |
| stabilization 名词 | /ˌsteɪ.bəl.ɪzˈeɪ.ʃən/ | 穩定化 /稳定化, 安定化 |
| upright 形容词 | /ˈʌpɹaɪt/ | 筆直 /笔直 |
| width 名词 | /ˈwɪtθ/ | 寬度 /宽度 |
| destabilize 动词 | /diːˈsteɪbɪlaɪz/ | 動搖 /动摇 |
| fingertip 名词 | /ˈfɪŋɡɚˌtɪp/ | 指尖 |
| kinetic 形容词 | /kɪˈnɛtɪk/ | 運動的 /运动的, 動的 /动的 |
| physicist 名词 | /ˈfɪzɪsɪst/ | 物理學家 /物理学家 |
| sharpen 动词 | /ˈʃɑɹpən/ | 磨, 削尖 |
| molecule 名词 | /ˈmɑ.lɪ.kjul/ | 分子 |
视频中出现的短语动词
| 单词 | 发音 | 释义 |
|---|---|---|
| fall down 动词 | /fɔl ˈdaʊn/ | 落下, 倒下 |
需要注意的发音
说话人用了 7 次缩略和弱读形式，例如 they're, you'd, can't。请按听到的简短形式来说。
- “th” 音: thousandth /ˈθaʊzən(d)θ/, width /ˈwɪtθ/, thermal /ˈθɜːməl/, mathematical /ˌmæθ(.ə)ˈmæt.ɪ.kəl/
- “sh” 和 “zh” 音: stabilization /ˌsteɪ.bəl.ɪzˈeɪ.ʃən/, sharpen /ˈʃɑɹpən/, equation /ɪˈkweɪ.ʒən/
- 长单词——注意重音位置: precarious /pɹɪˈkɛəɹi.əs/, stabilization /ˌsteɪ.bəl.ɪzˈeɪ.ʃən/, destabilize /diːˈsteɪbɪlaɪz/, inhibitor /ɪnˈhɪbɪtɚ/, mathematical /ˌmæθ(.ə)ˈmæt.ɪ.kəl/
如何用这段视频练习
- 先完整听一遍视频，不要开口，记下不认识的单词。
- 先用 0.75 倍速逐句跟读，熟练之后再回到正常速度。
- 录下自己的声音并与原声对比，特别注意 pencil, atom, pendulum 这类单词。
什么是跟读法？
跟读法 (Shadowing) 是一种有科学依据的语言学习技巧，最初开发用于专业口译员的培训，并由多语言者Alexander Arguelles博士普及。这个方法简单而强大：您在听英语母语原声的同时立即大声重复——就像是一个延迟1-2秒紧跟说话者的影子。与被动听力或语法练习不同，跟读法强迫您的大脑和口腔肌肉同时处理并模仿真实的讲话模式。研究表明它能显着提高发音准确性，语调，节奏，连读，听力理解和口语流利度——使其成为雅思口语备考和真实英语交流最有效的方法之一。