英语听力：自然百科 澳大利亚大堡礁 Great Barrier Reef—6

Like these sea fans, the last frontier of life on the reef. The divers reach their target-- a massive ridge, 190 feet down. Here, the air they are breathing is under pressure, squeezed down so that there's more gas in every lungful. They have to hope

英语听力：自然百科 澳大利亚大堡礁 Great Barrier Reef—7

The reef was left high and dry, exposed to air and harsh sun. A trillion tiny creatures died in their own homes. For the coral, it was an apocalypse. When the ice age ended, the sea came back and submerged the dead reef. But what brought it back to l

英语听力：自然百科 澳大利亚大堡礁 Great Barrier Reef—8

For thousands of years, this powerful current has regenerated the reef. But it can not repair everything. Beneath the waves lie deeper scarsthe largest coral reef on Earth is home to a dazzling diversity of marine species, some found nowhere else on

英语听力：自然百科 澳大利亚大堡礁 Great Barrier Reef—9

Here it is. Got it, I think. A spring. And whats actually coming out of this is fresh water. You can drink. You see this stuff bubbling out? This is what the traditional owners of this place call 'buiur bindi''fresh water in the ocean'. The locals ca

英语听力：自然百科 澳大利亚大堡礁 Great Barrier Reef—10

But the wonky holes will never be completely covered up, because coral cant grow in freshwater. Theyll remain an indelible reminder of the reef's past lives. But the origins of the reef lie even further back in time. And to understand them means crac

英语听力：自然百科 澳大利亚大堡礁 Great Barrier Reef—11

So we're looking at the core of the volcano which is referred to as Mount Warning. That peak extends up to just a little over 1, 1 00 meters. But when it was active, the peak of this volcano was 6, 000 feet high. Millions of years of wind and weather

英语听力：自然百科 澳大利亚大堡礁 Great Barrier Reef—12

All lava has a chemical signature that tells scientists where it came from and when it was erupting. The higher up the old volcano, the more pristine the rocks will be. They are the last remaining evidence of the eruption which created this volcano m

英语听力：自然百科 澳大利亚大堡礁 Great Barrier Reef—15

Today, the elements that support the reef are in fine balance--sun, wind and waves. But it doesn't take much to tip the balance, plummeting this huge reef into disaster. It might happen sonner than you think. Eighteen million years ago, a series of r

英语听力：自然百科 澳大利亚大堡礁 Great Barrier Reef—16

The pearl luggers then turned their attention to something else, a much bigger target. The reef has always provided a great haven for large animals, like turtles who nest on the coral piece. Whole populations of turtles were brought to the verge of e

英语听力：自然百科 澳大利亚大堡礁 Great Barrier Reef—17

One of the early methods to getting rid of a starfish was to cut them in half, then killing them with a knife, but starfish has this amazing property when they regenerate. Far from killing them, cutting these animals in half actually creates two of t

英语听力：自然百科 澳大利亚大堡礁 Great Barrier Reef—18

It's an astounding mechanism, but it looks like it's being overwhelmed. Recently, the coral has been telling us that its had enough. Because when it overheats, it self-destructs, expelling the algae that live with them. They turn deathly pale, a proc

英语听力：自然百科 澳大利亚大堡礁 Great Barrier Reef—13

Eighteen million years ago, it arrived in warm, tropical waters. Only then could the world's greatest reef be born. Australia's epic journey may have created perfect conditions for coral, but it also put it in the line of fire of the most powerful st

英语听力：自然百科 澳大利亚大堡礁 Great Barrier Reef—1

Where the forces of nature meet? In a hidden world, a tropical miracle. At this moment, evolution is building a living colossus, a giant built by nature's tiniest creature, a model of reincarnation, a survivor born from disasterthe Great Barrier Reef

英语听力：自然百科 澳大利亚大堡礁 Great Barrier Reef—2

Where every plant and animal helps sustain the whole.The waste from parrot fish cements the reef. Stinging anemones provide a haven to the vulnerable. Even killers play their part, preventing a population explosion that would destroy this fragile eco

英语听力：自然百科 澳大利亚大堡礁 Great Barrier Reef—3

As a polyp grows, it puts up a wall of limestone around itself. And then it multiplies. Each polyp can produce thousands of offspring, which all work together to build a living fortress-- a coral reef. After just a few years, a single piece of coral

英语听力：自然百科 澳大利亚大堡礁 Great Barrier Reef—4

Inside the flesh of these tiny animals are microscopic plants called algae, but these aren't parasites. None of this would be here without them. Wachenfeld: When the algae photosynthesize, they take energy from sunlight and carbon dioxide, then make

英语听力：自然百科 澳大利亚大堡礁 Great Barrier Reef—5

shows it really quite well. In order to bring back a piece of this mystery, his team of divers will be risking their lives. Diving problems, you got currents, tides, waves. We havent been here before. We haven't been this deep, though. One of those c

2007年VOA标准英语-West Bank Barrier, New Divide in Palestinian-Is

By Jim Teeple Jerusalem 14 June 2007 The human rights group Amnesty International has called for the dismantling of the Israeli security barrier in the West Bank. The London-based group says the barrier has had a disastrous impact on the lives of Pal

学个词Learn a Word 第239期 Barrier

今天我们要学的词是barrier。 Barrier是障碍的意思。Language barrier, 是语言障碍。Trade barrier, 是贸易壁垒。The lack of funding was the biggest barrier to the road improvement, 意思是道路改善的最大障碍是缺少资

2007年VOA标准英语-Historic Superbowl Shatters Racial Barrier in A

By Brian Padden Washington, D.C. 06 February 2007 watch Racial Barrier report The Superbowl is not only the championship final of the National Football League in the United States, it is also the country's most watched sporting event of the year. Th