跟读练习: What Exactly Is Coral? - 通过视频学习英语口语

What is coral?

From a distance, it looks like mossy rock or bone.

Up close, it appears to be covered in tiny flowers.

But each of those flowers are actually an animal.

A coral pollen.

A round body topped with a mouth surrounded by a ring of tentacles.

Inside, there is a simple gut lined with long threads of tissue that help digest the coral's food.

Reef-building corals lay down a skeleton of calcium carbonate, essentially rock.

Corals are colonial, budding off new polyps, each one connected to the one next to it,

and genetically identical, forming a living veneer.

Corals are hunters.

Their tentacles are lined with millions of stinging cells that kill what they catch.

They are super weapons on a micro scale.

But in the clear, warm water where corals live, there's not much to catch.

So, how do corals find food?

The secret to their success is in their relationship with a plant.

Living right inside their cells are tiny algae, plant cells known as symbionts.

Like all plants, they photosynthesise.

Using energy from the sun, they produce sugars, enough food for themselves and for their coral host.

It's extraordinary biology, an almost alien relationship where the algae gets a home

and the coral gets up to 90% of its food.

And together, they build the reef.

But because of warming oceans, there's been a massive breakdown in this crucial relationship.

And the reef as we know it is disappearing fast.

If science can help the reef survive, The answer may lay halfway around the world.

On a tiny Hawaiian island, scientists are trying to understand the connection between coral and the plant inside them,

and use that knowledge to speed up evolution.

I'm at the Hawaiian Institute of Marine Biology, where Ruth Gates does her research.

It's an ideal facility.

Over here you can grow corals, and over here you can grow hammerhead sharks.

But what's really amazing is that we are right on a coral reef.

Dr Ruth Gates has been studying corals for over 25 years, inspired by a love of the reef.

The coral reef is a vibrant natural city.

It's got texture, it's got colour, it's got movement.

You're surrounded by extraordinary things.

Ruth and her team are investigating the mechanism of coral bleaching.

What happens when temperatures get too high for coral?

Hi.

Great to see you.

What a beautiful lab.

Welcome.

This special microscope lets Ruth and biologist Amy Eggers raise the water temperature to simulate warming oceans

and observe what happens to living coral as it bleaches.

This is the only microscope in the world that's equipped to simulate future ocean conditions

that allows you to visualise a living organism.

So you can really see how it's a colonial animal here, can't you?

All of those polyps.

The number of algal cells, or symbionts, living throughout the coral is staggering.

Around a million in every square centimetre, an area the size of your thumbnail.

Coral builds the reef structure that supports so much other life, so it's called a foundation species.

If coral is a foundation species, then the symbiotes themselves are clearly a keystone species,

because the coral cannot survive without them.

And if the coral doesn't survive, the reef will not survive.

When ocean temperatures get too high, the coral rejects the algae living inside it inside it in the process called bleaching.

Coral bleaching is really the breakdown of this relationship between these plant cells and the animal itself.

The plant cells react to high temperature and instead of creating food, they produce an irritant to the coral.

When the animal gets stressed, somehow they break the connection and the plant cells are ousted from the system.

Some corals belch clouds of their life-giving algal cells.

Others release them over days in tiny clumps.

What you see as the coral goes pale is just the clear tissues of the animal overlaying the white skeleton.

Bleached but still living coral can clearly be seen under powerful magnification.

It's become a ghost coral, hasn't it?

All the structure is still there but none of the colour, none of the vibrancy.

That is a spooky image.

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。

跟读练习: What Exactly Is Coral? - 通过视频学习英语口语

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什么是跟读法？