Pratique du Shadowing: What Happens To Nuclear Waste? - Apprendre l'anglais à l'oral avec la vidéo

Création de la leçon...
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When you pass a nuclear power plant in the distance as you drive down the road, it's impossible not to think about the power that those towering buildings hold.
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Scientist Enrico Fermi supervised the opening of the first nuclear reactor in 1942, and now our landscapes are dotted by mighty nuclear power plants.
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These powerful energy plants provide over a fifth of the United States' electricity
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and don't have the carbon footprint of other energy sources like coal and fossil fuels, so why not build more?
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One reason?
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Nuclear waste and radioactivity.
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When managed correctly, nuclear power plants are processing powerful radioactive energy
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that needs to be disposed of correctly to keep the environment and the people handling it safe.
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And if someone wasn't handling the planet's safety correctly, like a certain bald bumbler from Springfield, things could go very badly.
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Dope.
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The risks of nuclear energy become crystal clear in 1979 in Londonderry Township, Pennsylvania, at the Three Mile Island nuclear plant.
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While the reactors were stable, a failure in the mechanical systems regulating the safe venting of gases broke down
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and allowed a large amount of nuclear reactor coolant to escape.
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That led to a partial meltdown of reactor two, creating a major radiation leak near the city of Harrisburg.
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A voluntary evacuation of a 20 -mile radius around the plant followed.
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Thankfully, no one in the plant was injured and later tests showed no increased risk of cancer, but it took 15 years to clean up the surrounding area.
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It It remains the worst nuclear accident in United States history, but is dwarfed by the massive nuclear meltdown at Chernobyl
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which caused major casualties and rendered areas surrounding the Ukrainian plant uninhabitable to this day.
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Given the risks, it's no surprise that nuclear waste and by -products are strictly regulated by the government.
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Modern nuclear plants keep waste to a minimum by recycling used fuel back into the uranium -based and mixed oxide fuel,
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but 4 % of nuclear waste can't be processed and remains highly radioactive.
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Radioactivity is a waiting game as the toxic quality of the waste decreases over time,
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measured in half -life, or the time it takes for a radioactive substance to reduce to half of its nuclear value.
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The time it takes for nuclear waste to neutralize varies wildly.
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Some common isotopes, like strontium -90, have a half -life of around 30 years,
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but other powerful artificial nuclear isotopes like plutonium -239 have a half -life of over over 20 ,000 years.
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Not only is it radioactive enough to kill anyone exposed to it, but it could be an unpleasant surprise for whoever digs it up in the far future.
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Nuclear power plants operate in 31 countries, including all of the world's largest economies, and much of Asia and Africa are planning new builds.
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The regulation of nuclear waste is overseen by the International Atomic Energy Agency's Joint Convention on Spent Fuel Management, and they work to keep the world safe life.
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The risks of exposure to nuclear waste include higher risk of cancer, higher risk of birth defects in pregnant women, and in high concentrations, organ failure, and death.
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Most nuclear waste comes from nuclear power plants and nuclear arms, but medical and industrial waste and natural radioactive materials also pose a risk.
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Nuclear waste comes from two main sources, front -end and back -end.
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Front -end nuclear waste comes from the extraction of uranium and contains radium.
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The depleted uranium that comes from it is extremely dense
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and is often recycled into anti -tank shells and other metals where extreme durability is needed.
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Back -end nuclear waste comes from spent fuel rods and is packed with beta and gamma radiation.
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These powerful energies come with extremely long half -lives and are formed in nuclear reactors.
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Some of the most challenging waste to dispose of comes from nuclear weapons materials, and the plutonium used to create these powerful bombs is extremely difficult to separate and isolate.
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That makes nuclear weapon disposal a growing concern, especially in the aftermath of the Cold War when the US and Russia drastically slashed their nuclear arsenals.
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The world is less likely to end now, but what are we going to do with all those things that can end the world?
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The classification of nuclear waste determines the priority level of the processing and disposal.
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The lowest priority nuclear waste is uranium mill tailings, which are created by the rough processing of uranium ore.
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While they don't contain a high level of radioactivity, they have long half -lives and are full of metals with other health risks like arsenic and lead.
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Low -level waste is the most common waste type because it's anything that came into contact with radioactivity.
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Common in hospitals and processing plants, it can include paper, clothing, tools, and filters that are used by people working with nuclear energy.
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These objects pick up trace levels of radioactivity and should be disposed of safely instead of being processed with standard trash.
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Intermediate waste is usually the byproduct of nuclear processing and is harder to dispose of than low -level waste.
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Resins, chemical sludge, and metal coverings
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that have been exposed to nuclear energy long -term pick up the harmful radioactivity and the hazardous nature builds over time.
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When breaking down a nuclear reactor for decommissioning, even the building materials surrounding the core can build up radioactivity.
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Before disposing of this waste, it should be safely shielded to prevent exposure.
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Then there's high -level waste, and this is what everyone thinks about when they hear about nuclear power plants.
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The alarms start blaring, the hazmat suits go on, high -level nuclear waste is as radioactive as you think.
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But the good news is, there are effective ways to contain it.
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When a nuclear fuel rod serves its purpose and is taken out of the core, it becomes high -level waste.
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While the number of high -level waste objects is small compared to the other classes,
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the level of radioactivity is so high that it accounts for over 95 % of total radioactivity caused by nuclear energy.
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While most radioactive isotopes produced by high -level waste are high -powered but have a short half -life,
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the presence of isotopes like plutonium makes it critical to ensure it's contained safely.
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So what's the best way to dispose of nuclear waste?
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That's what nuclear energy -using countries have been arguing over for decades.
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Most experts say the best solution for long -term disposal is
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by constructing a deep underground facility similar to a mine
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that can contain large amounts of high -level waste away from humans and be sealed up in between disposals.
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But that's easier said than done, and no country has finished one, although Finland is close to completing their Onkalo spent nuclear fuel repository on the west coast.
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Currently countries use a number of alternative systems that are considered safe, but imperfect.
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The first step to minimize the impact of nuclear waste on the environment is to neutralize it as much as possible.
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This is done by processing it and stabilizing it into a form that loses its explosive properties.
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Some countries mix the waste with sugar and then calcinate it into a solid object by processing it through a rotating tube.
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Turned into glass, the waste products are then bonded to the other molecules and then poured into stainless steel and sealed.
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They are then stored underground, where the waste products are trapped for thousands of years without leaking radioactivity into the environment.
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Other technologies include ion exchange, where medium -level wastes are neutralized by concentrating the radioactivity into much smaller volumes.
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This makes them easier to contain, but isn't recommended with volatile high -level wastes.
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But when the time range for nuclear waste to become deactivated can reach into the millennia or longer, with some rare isotopes having a half -life of over a million years,
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scientists are concerned that these storage methods can come back to haunt us.
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That's why we've eliminated many of the more short -sighted methods of nuclear waste disposal, like ocean disposal.
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Up until the 1990s many countries, including the United States and the Soviet Union, would dump drums of contained nuclear waste into the ocean, especially in the coastal regions of Somalia.
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Somalia hasn't had a functioning government since the 1990s, and the pirates weren't going to mess with a large ship bearing a country's flag
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when they could go after smaller merchant ships, so countries thought anything goes out there there.
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The Arctic Ocean was also a popular choice for the Soviets, as they controlled a huge coast in the north.
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Overall, 137 ,000 tons were dumped in the water by European countries in 34 years, and it took its toll on the oceans.
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Tests of areas where dumping was common found elevated levels of radioactivity, and in 1993 a treaty was passed banning ocean disposal of nuclear waste.
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The most common current method for nuclear waste disposal is above -ground disposal, where Their waste is sealed up in a steel cylinder with an inert gas
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that won't react with it and then sealed in radiation -shielding concrete.
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The radiation -proof drums are then sealed in a storage facility near the nuclear power plant.
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This is how big plants handle their waste in -house, and it's popular for a few reasons.
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First, it's handled internally and the plant doesn't have to get approval
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and fight their way through government red tape to find a dumping facility.
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Second, it's inexpensive and doesn't require construction or expensive materials.
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Finally, the waste remains on site for reprocessing, which remains the best solution for solving the nuclear waste question.
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But the secret weapon for eliminating nuclear wastes is chemists and physicists,
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as these scientists have developed ways to chemically separate fission products and unused uranium from used nuclear fuel.
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This started by extracting plutonium, with its long half -life, from nuclear fuel to be used in the construction of nuclear weapons.
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But as the focus shifted from bombs to energy plants, scientists developed ways to create a new type of nuclear fuel from the remnants of the old.
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Mox nuclear fuel, or mixed oxide fuel, is created in high -level facilities from nuclear waste coming from plants around the country,
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and has become a top way of disposing of nuclear waste in Europe.
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In America, the government's focusing on research, and commercial nuclear fuel reprocessing isn't widespread yet.
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So what will nuclear waste disposal look like in the future?
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One of the biggest possibilities is space disposal, as this will get the radioactivity as far away from people as possible.
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The problem, besides the possibility of poisoning some aliens that will come looking for revenge, is that technology isn't there yet.
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While technology like mass drivers and space elevators is in development, the carrying capacity of our current space shuttles is limited
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and would only be able to carry a small amount of nuclear waste.
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The money that goes into every space shuttle launch is high, and the program is far from foolproof.
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The loss of the Challenger and Columbia shuttles proved that a catastrophic accident is possible,
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and a space shuttle disaster carrying a nuclear payload could contaminate a large area.
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But could we transform nuclear waste into less harmful waste with a shorter half -life?
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That was the dream of scientists behind the Integral Fast Reactor, an experimental reactor that would use a nuclear fuel cycle that reprocessed fuel through electro -refining.
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It would extract almost all the energy contained in uranium, medium, cutting fuel requirements by two orders of magnitude.
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Unfortunately the design had problems with leaking cooling fluid, and the project was cancelled by the US government in 1986.
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But research is ongoing, and new fission reactors
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that have much more processing power than the traditional light water reactors are under development now.
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The earth itself might be our best ally for disposing of nuclear waste, as man -made structures underground are the top proposal for future storage facilities.
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By digging out large, stable bunkers in sparsely populated areas of a country,
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nations could keep their nuclear waste in a centralized location and reduce the risk of leaks happening in multiple locations.
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Deep borehole disposal is an alternative that creates narrower
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but much deeper holes capable of storing the waste up to three miles under the earth, where any leaks would be far away from humans.
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The big holdup?
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Besides developing the technology for safe deep earth drilling, getting approval from governments is a holdup.
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Many countries have rejected proposals out of fears that the disposal won't be safe, or that it could destabilize the ground.
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The consequences of a nuclear accident are massive and long -term, as the residents of Pripyat, Ukraine know all too well.
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In the heart of the Chernobyl nuclear plant is the elephant's foot, a mass of solid nuclear waste caused by the 1986 meltdown.
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Dense and hard to damage, it was so radioactive when released that it would kill anyone who was in the same room with it.
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Today, over 30 years later, it's still highly radioactive and poses major health risks to anyone who's exposed.
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So however we neutralize our nuclear waste, let's make sure it stays there.

Vocabulaire et conseils d’expression pour cette leçon

Cette vidéo contient 124 phrases et 2198 mots à répéter en shadowing. La partie parlée dure 11:54. Le locuteur parle vite, environ 185 mots par minute : attendez-vous à des liaisons et à des sons réduits. 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

15 mots de la vidéo à retenir, avec leur prononciation et leur sens :

MotPrononciationSens
disposal nom/dɪsˈpoʊ.zəl/disposition
reactor nom/ɹiˈæktɚ/réacteur
radioactive adjectif/ˌɹeɪdioʊˈæktɪv/radioactif
dispose verbe/dɪsˈpoʊz/se débarrasser de, éliminer
uranium nom/ˌjuː.ˈɹeɪ.ni.əm/uranium
seal nom/siːl/sceau, cachet
leak nom/liːk/fuite, voie d'eau
radiation nom/ˌɹeɪ.diˈeɪ.ʃən/radiation
dump verbe/dʌmp/se débarrasser de
shuttle nom/ˈʃʌtəl/navette
underground adjectif/ˌʌn.dəɹˈɡɹaʊnd/souterrain
safely adverbe/ˈseɪfli/prudemment
correctly adverbe/kəˈɹɛk(t).li/correctement
surround verbe/səˈɹaʊnd/entourer, cerner
meltdown nom/ˈmɛltˌdaʊn/fusion du cœur d'un réacteur nucléaire

Les verbes à particule que vous entendrez

MotSens
break down verbetomber en panne
pick up verbesoulever
build up verbes'accumuler, s'entasser
clean up verbenettoyer
dig out verbedénicher
go out verbesortir

La grammaire de cette vidéo

Les structures que le locuteur utilise le plus, avec les mots exacts de la vidéo :

StructureDans la vidéo
Voix passive be + participe passé — l’accent est mis sur ce qui arrive, pas sur qui le faitare dotted · be disposed · was injured
Present perfect have/has + participe passé — une action passée qui compte encore maintenanthave been exposed · has finished · we've eliminated
Propositions relatives who / which + proposition — une précision sur une personne ou une chosetailings, which are · anyone who was

Prononciation à surveiller

Le locuteur utilise 14 contractions et formes réduites, comme isn't, doesn't, don't. Prononcez-les sous leur forme courte, telles que vous les entendez.

  • Les sons « th »: clothing /ˈkloʊðɪŋ/, aftermath /ˈæf.tɚˌmæθ/
  • Les sons « sh » et « zh »: radiation /ˌɹeɪ.diˈeɪ.ʃən/, shuttle /ˈʃʌtəl/, exposure /ɪkˈspəʊ.ʒə(ɹ)/, trash /tɹæʃ/, shell /ʃɛl/
  • Mots longs — placez bien l’accent: radioactive /ˌɹeɪdioʊˈæktɪv/, uranium /ˌjuː.ˈɹeɪ.ni.əm/, radiation /ˌɹeɪ.diˈeɪ.ʃən/, priority /pɹaɪˈɒɹɪti/, eliminate /ɪˈlɪm.ɪ.neɪt/

Comment s’entraîner avec cette vidéo

  1. Écoutez la vidéo en entier une fois sans parler et notez les mots que vous ne connaissez pas.
  2. Commencez à la vitesse 0,75×, répétez phrase par phrase, puis revenez à la vitesse normale quand cela devient facile.
  3. Enregistrez-vous et comparez avec l’original, en faisant attention à des mots comme disposal, reactor, radioactive.

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.

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