Pratique du Shadowing: Trees Are So Weird - Apprendre l'anglais à l'oral avec la vidéo
Choisissez un mode d'entraînement
Chaque mode ouvre une salle d'entraînement en plein écran.
106 phrases
Si les phrases sont trop courtes ou trop longues, cliquez sur Edit pour les ajuster.
1
Every tree you have ever seen is dead.
2
It turns out the alive part of a tree is just a tiny, paper thin strip of cells, trapped between a dead skeleton and dead outsides.
3
Trees are some of the most extreme beings on earth with one of the most unique strategies in nature – on top of being mostly dead stuff, they forge their body out of thin air, they mercilessly crush rocks with acid, and they have an internal negative pressure that would kill you instantly.
4
So, how do trees actually work?
5
Let’s go back…to the beginning.
6
The Ancient Battle for the Sky For over a billion years the ancestors of plants only inhabited the sun drenched surfaces of the oceans.
7
Their bodies were thin and delicate and absorbed water straight through their surfaces, getting their energy through photosynthesis.
8
Forging sunlight, carbon dioxide and water into sugar.
9
But about 470 million years ago they decided to conquer a hostile alien planet: the land.
10
Like green rugs with ambition these plant ancestors began clinging to the ground wherever it was wet and damp.
11
But now, with solid ground beneath and no ability to float around a new dimension became a place of intense warfare: up.
12
The higher they grew, the more sun they would get, while starving their competition below.
13
Height became a deadly weapon. The battle for the sky had begun.
14
Until now, plants were built mostly from cellulose, which was great for shape, but not for strength, which limited how tall they could grow.
15
Over dozens of millions of years of evolutionary warfare, a group of plants developed one of life's greatest breakthroughs: lignin.
16
Lignin is a macromolecule made of ring-shaped structures.
17
It is rigid, tough, waterproof, and incredibly hard to break down.
18
Concrete in a world made of jelly.
19
It filled gaps between cellulose threads, stiffening and locking everything into place.
20
Lignin gave plants the strength to grow taller and claim the sun for themselves.
21
But of course now they were competing with each other, which must have been really annoying for them.
22
So as more millions of years passed, some plants just went all in on lignin and produced more and more of it, becoming stiffer, harder and stronger.
23
Until one day, around 385 million years ago they got the biological equivalent of steel reinforced concrete: wood.
24
More on it later, but with this magic material the first trees emerged.
25
Almost immediately they became the largest living beings alive, shooting up to 20 meters high into the sky – and they only got bigger from here.
26
But this enormous size created extremely hard problems: How do you get water from the ground up to the green parts that do the actual photosynthesis?
27
And how do you get the sugar they produce down to the cells that keep you up there?
28
On the scale of a cell a distance of a few meters is like you’re working in Britain while your lunch box is in Egypt and your drink in New York.
29
How do you not die?
30
So trees came up with one of the most amazing ways any organism grows, and became nearly immortal by accident.
31
A Conveyor Belt of Death Let us slice an ancient tree in half and get to the heart running it all: the cambium, a razor-thin, circular zone, just a few stem cells wide.
32
These stem cells grow inward and outwards, turning into two groups of specialists.
33
The inward specialists are on a conveyor belt of death, the xylem.
34
With each new division it is pushing the cambium outwards, making the tree thicker the older it gets.
35
As the xylem cells mature their lignin production goes into overdrive, and they become hard and stuffy, like a muscle slowly transforming into bone.
36
They begin to hollow themselves out, shedding everything that once made them alive.
37
And then they die.
38
What’s left is a corpse, a hard, empty tube.
39
As the tree grows year after year, new corpses are layered on old corpses, forming rings of hardened, dead tissue.
40
A graveyard of trillions of plant bones.
41
This is what we call wood.
42
Stacked together they form a giant network of pipes that stretches the whole length of the tree.
43
This network uses the chemical properties of water and a few other tricks to move it with incredible efficiency.
44
Water molecules are, for a lack of a better word, sticky, like tiny magnets, and naturally cling tightly to each other.
45
When one moves, it pulls the next along with it, like pulling on a rope.
46
In trees this rope starts in the roots and ends in the leaves that bathe in the warmth from the sun.
47
Here the heat from the sun evaporates 95% of the water that got sucked into the roots, from billions of tiny pores, releasing a constant invisible mist of water molecules around the crown of the tree.
48
This process, called transpiration in plants, creates tension on the rope of water molecules, stretching and lifting the entire column upwards, all the way from the roots to the leaves.
49
This pull is so insanely strong that it can lift water over 100 meters, which requires sucking forces equivalent to the pressure of dozens of atmospheres – as much as the crushing pressure hundreds of meters deep in the ocean.
50
Nothing humans have ever built comes even close to this power.
51
Even our best machines can’t pull water higher than about 10 meters, because the negative pressure required to pull hard enough makes it boil.
52
But the water pipes of trees are so tiny and narrow, almost perfectly airtight that despite the insane suction pressure inside a tree, water stays liquid and reaches the top.
53
As the tree ages old xylem cells eventually stop working and fill up with resins and other protective substances.
54
Slowly they turn into heartwood, a dense, chemically fortified core that is extremely resistant to decay.
55
The core of a mighty tree.
56
But water is only one half of the story.
57
The sugar produced in the sky needs to be transported to nourish cells down below.
58
And cells from the roots to the leaves need to coordinate and exchange information about damage and growth.
59
This is the job of the cambium stem cells that grow outwards: the phloem.
60
The Tiny Living Part of the Tree As the Cells of the phloem grow outwards they separate into three teams and make a brutal compromise.
61
The first group are Sieve cells and their grim fate is to become a living transport system.
62
Although “living” is not exactly right.
63
As they mature they start to destroy themselves, digest their organelles and even their nuclei that houses their genetic code.
64
At the same time they hollow themselves out, connecting to the sieve cells above and below them.
65
This goes on until they are a sad shadow of living beings.
66
A drooling, living tool without a brain or arms, unable to support themselves.
67
Only the second group, their companion cells, keeps them alive.
68
They connect with the crippled Sieve cells via tiny channels and start maintaining them.
69
Sending over energy, instructions or repairing them if needed.
70
Running along the entire tree, these two teams form a tiny and very thin layer of living sugar pipelines and signal cables that stretch throughout the entire body.
71
Providing food and information wherever it is needed in the tree.
72
The third team are Parenchyma cells, the silent workers of the tree that are carrying out essential labor in the background.
73
Some are like mini pantries that store nutrients, sugars or water that the tree uses to survive the winter, when it is unable to produce food.
74
Others are like mini healers that can repair damage, while some go onto the offensive and create toxins and anti fungal bio weapons to kill intruders.
75
On top of the phloem sits another layer of stem cells.
76
They are producing a second conveyor belt of death, moving outside.
77
Special cells grow from this layer and as they mature, just like the xylem cells in the center, they kill themselves for the team, turning into a hard guard wall – the bark.
78
Just like your skin, it protects the tiny living layer from damage, parasites and invaders.
79
So what is a tree?
80
The living part of the stem is really just this extremely thin and tiny layer, a few millimeters thick, sitting on a thick mountain of cell corpses, surrounded by another layer of cell corpses.
81
The vast majority of the biomass of a tree is dead.
82
This is also why you really should not damage the bark of trees because while it seems you are only doing a little damage, you are actually killing the living part of the tree.
83
But unless a tree is stopped by droughts, diseases, storms or a human axe, this system of being mostly dead kind of makes trees potentially immortal.
84
They don’t age like we do, in principle they could grow this way nearly forever.
85
Which is why we still have trees around that were born when the Egyptians started building their first pyramid, 5000 years ago.
86
Really what kills a tree is the world around it.
87
Trees are not a real biological category but one of the most successful ideas life has ever had, and many different species developed on their own.
88
These plants won the battle for the sky, solved every challenge that had kept plants small and fragile and they took over the planet in a few million years.
89
Even today three trillion of them cast their majestic shadows.
90
But we’ve barely covered half of it: on top and below there are the crown and the root system – one building the tree from air, another mining minerals with acid and involved in complex communications with fungi and other trees.
91
There’s so much more to talk about, so we’re already working on the next part - stay tuned!
92
Trees are truly incredible – but many of our most beautiful forests are disappearing fast and we’re running out of time to protect what’s left.
93
That’s why we have partnered up with Planet Wild.
94
Planet Wild is a community-based nature protection organization that supports conservation projects around the globe.
95
Every month, their community of over 15,000 members funds a new mission to restore nature.
96
We at kurzgesagt really value transparency.
97
That’s why we love that Planet Wild documents all their missions in video reports right here on YouTube so you can see what your contribution helped achieve.
98
Take their underground forest mission in Tanzania: While you think this desert is dead, there’s actually life still here.
99
Beneath the surface, underground forests are just waiting to grow.
100
And with an ancient technique, Planet Wild helped make that happen.
101
If you would like to help our planet’s ecosystems, consider joining Planet Wild.
102
You can give any amount that feels right to you – every dollar counts.
103
The first 100 people to sign up using our code KURZGESAGT11 will get their first month paid for by us!
104
Just scan the QR code or click the link in the description.
105
Make a tree friend, and join the Planet Wild community – today.
106
If you want to see them in action first, check out their underground forest mission here.
Télécharger l'application
Tout pour parler couramment
Prononciation IAChaque phrase notée
Phonétique (IPA)Maîtrisez chaque son
VocabulaireEnrichissez votre lexique
Jeu de vocabulaireApprenez en jouant
Même chaîne
C15
How Does Ketamine Work?
Daily ConversationUniversity Students
C13
What If We Cool Down the Sun?
Daily ConversationUniversity Students
C12
Touchscreens – How Do They Work?
Daily ConversationUniversity Students
C11
What Actually Happens When You Die?
Daily ConversationUniversity StudentsWorking Adults
C259
We Made A New Channel!
University StudentsWorking Adults
C15
We Traveled Back in Time. Now Physicists Are Angry.
Daily ConversationUniversity StudentsWorking Adults
C17
How Caffeine Works
Daily ConversationUniversity Students
C121
Queen Ant Clones Another Species
Daily ConversationUniversity Students
C113
Would You Upload Your Mind?
Daily ConversationUniversity StudentsWorking Adults
C111
You Will Only Like Half of This Video
Daily ConversationUniversity StudentsWorking Adults
B26
YOU Own the Moon. And Mars. And Venus.
Daily ConversationUniversity StudentsWorking Adults
C1149
How Antidepressants Work
Daily ConversationUniversity StudentsWorking Adults
B238
Your Brain Peaked at Birth
Daily ConversationUniversity StudentsWorking Adults
C212
Let’s Travel to The Most Extreme Place in The Universe
IELTS PrepTOEFL PrepUniversity Students
C174
We Won’t Explore the Galaxy...
IELTS PrepTOEFL PrepUniversity Students
B26
Dozens of Nukes Are Missing. Why? HOW?
Daily ConversationWorking Adults
C1153
Something Travels Faster than Light
University StudentsWorking Adults
C14
How to Destroy a Black Hole
University StudentsWorking Adults
B22
Do we Need Nuclear Energy to Stop Climate Change?
Daily ConversationWorking Adults
C182
The Deadliest Thing in Your Kitchen
University StudentsWorking Adults
FOR YOU
Vidéo recommandée
C113
98 phrases
Why Are There No Holes Around Trees?
IELTS PrepTOEFL PrepUniversity Students
C12
9 phrases
Our Greatest Delusion
IELTS PrepTOEFL PrepUniversity Students
C13
160 phrases
What Actual Aliens Might Look Like
IELTS PrepTOEFL PrepUniversity Students
C12,014
12 phrases
Nature Is Speaking: Shailene Woodley is Forest
IELTS PrepTOEFL PrepUniversity Students
C13
55 phrases
Vol 3 - test 6 - section 4
IELTS PrepTOEFL PrepUniversity Students
C1158 phrases
Introduction to Biology: Crash Course Biology #1
IELTS PrepTOEFL PrepCambridge Exam Prep
C14
156 phrases
The banana is under threat
IELTS PrepTOEFL PrepUniversity Students
C110
144 phrases
What Did Ancient Humans Do at Night?
IELTS PrepTOEFL PrepUniversity Students
C14
149 phrases
Why Humans Run the World - Yuval Noah Harari on TED
IELTS PrepTOEFL PrepUniversity Students
C15
41 phrases
The Building Blocks of Everything: Matter & its Properties
IELTS PrepTOEFL PrepUniversity Students
C11
64 phrases
What Exactly Is Coral?
IELTS PrepTOEFL PrepUniversity Students
C12
270 phrases
The Most Misunderstood Concept in Physics
IELTS PrepTOEFL PrepUniversity Students
Vocabulaire et conseils d’expression pour cette leçon
Cette leçon d’expression orale de niveau C1 s’appuie sur la vidéo « Trees Are So Weird ». Les mots qui reviennent le plus souvent : tree, cell, plant, grow, tiny. Cette vidéo contient 106 phrases et 1866 mots à répéter en shadowing. La partie parlée dure 11:09. Le locuteur parle à un rythme naturel d’environ 167 mots par minute, proche d’une conversation courante. Seuls 80 % des mots font partie des 3 000 mots les plus courants en anglais, le vocabulaire est donc exigeant.
Vocabulaire clé de cette vidéo
Les 15 mots les plus avancés de la vidéo, avec leur prononciation et leur sens :
| Mot | Prononciation | Sens |
|---|---|---|
| meter nom | /ˈmitəɹ/ | mètre, compteur |
| xylem nom | /ˈzaɪ.ləm/ | xylème |
| cambium nom | /ˈkeə̯m.biˌəm/ | cambium |
| conveyor nom | /kənˈveɪɚ/ | convoyeur |
| phloem nom | /ˈfloʊ.əm/ | phloème |
| sieve nom | /sɪv/ | tamis, crible |
| molecule nom | /ˈmɑ.lɪ.kjul/ | molécule |
| rope nom | /ɹoʊp/ | corde |
| ancestor nom | /ˈæn.sɛs.tɚ/ | ancêtre |
| cellulose nom | /ˈsɛljəloʊs/ | cellulose |
| inward adjectif | /ˈɪnwəd/ | intérieur |
| photosynthesis nom | /ˌfoʊ.toʊˈsɪn.θə.sɪs/ | photosynthèse |
| immortal adjectif | /ɪˈmɔɹtəl/ | immortel |
| bark nom | /bɑɹk/ | écorce |
| hollow adjectif | /ˈhɑloʊ/ | vide, creux |
Les verbes à particule que vous entendrez
| Mot | Prononciation | Sens |
|---|---|---|
| break down verbe | tomber en panne | |
| carry out verbe | /ˈkæ.ɹi aʊt/ | sortir, transporter dehors |
| check out verbe | mater, regarder | |
| come up with verbe | inventer, imaginer | |
| run along verbe | partir | |
| sign up verbe | inscrire | |
| take over verbe | reprendre | |
| turn out verbe | se finir, se terminer |
La grammaire de cette vidéo
Les structures que le locuteur utilise le plus, avec les mots exacts de la vidéo :
| Structure | Dans la vidéo |
|---|---|
| Voix passive be + participe passé — l’accent est mis sur ce qui arrive, pas sur qui le fait | were built · are layered · be transported |
| Present perfect have/has + participe passé — une action passée qui compte encore maintenant | have ever seen · have ever built · has ever had |
Prononciation à surveiller
Le locuteur utilise 6 contractions et formes réduites, comme we're, can't, don't. Prononcez-les sous leur forme courte, telles que vous les entendez.
- Les sons « th »: photosynthesis /ˌfoʊ.toʊˈsɪn.θə.sɪs/, warmth /wɔɹmθ/, breakthrough /ˈbɹeɪk.θɹuː/
- Les sons « sh » et « zh »: evolutionary /ˌiː.vəˈluː.ʃən.ɛɹ.i/, ambition /æmˈbɪʃ.ən/, dimension /daɪˈmɛn.ʃən/
- Mots longs — placez bien l’accent: photosynthesis /ˌfoʊ.toʊˈsɪn.θə.sɪs/, inhabited /ɪnˈhæbɪtɪd/, organism /ˈɔɹ.ɡəˌnɪz.əm/, ecosystem /ˈikoʊˌsɪstəm/, evolutionary /ˌiː.vəˈluː.ʃən.ɛɹ.i/
Les sons difficiles pour les francophones :
- /h/ — il se souffle, il n’est pas muet: hollow /ˈhɑloʊ/, inhabited /ɪnˈhæbɪtɪd/, harden /ˈhɑɹdn̩/, hostile /ˈhɑstəl/
- /tʃ/ et /dʒ/ — à ne pas adoucir en « ch » et « j »: drench /dɹɛnt͡ʃ/, majestic /məˈd͡ʒɛstɪk/, digest /daɪˈd͡ʒɛst/, rigid /ˈɹɪd͡ʒ.ɪd/, jelly /ˈd͡ʒɛli/
- /r/ anglais — langue recourbée, sans frotter la gorge: meter /ˈmitəɹ/, rope /ɹoʊp/, immortal /ɪˈmɔɹtəl/, bark /bɑɹk/, warfare /ˈwɔɹfɛɹ/
Comment s’entraîner avec cette vidéo
- Écoutez la vidéo en entier une fois sans parler et notez les mots que vous ne connaissez pas.
- Commencez à la vitesse 0,75×, répétez phrase par phrase, puis revenez à la vitesse normale quand cela devient facile.
- Enregistrez-vous et comparez avec l’original, en faisant attention à des mots comme meter, xylem, cambium.
Qu'est-ce que la technique du Shadowing ?
Le Shadowing est une technique d'apprentissage des langues fondée sur la science, développée à l'origine pour la formation des interprètes professionnels. Le principe est simple mais puissant : vous écoutez de l'anglais natif et le répétez immédiatement à voix haute — comme une ombre suivant le locuteur avec un décalage de 1 à 2 secondes. Les recherches montrent une amélioration significative de la précision de la prononciation, de l'intonation, du rythme, des liaisons, de la compréhension orale et de la fluidité.