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

 It's an astounding¹ mechanism², but it looks like it's being overwhelmed. Recently, the coral has been telling us that it’s had enough. Because when it overheats, it self-destructs, expelling the algae³ that live with them. They turn deathly pale, a process known as bleaching⁴. It's a desperate measure will eventually kill them. So, Ove is constantly monitoring the reef to see which corals are at risk.

 

“Now there’s no point in using these instrument on these corals, because they are dead.”

 

A temperature rise of just two degrees will wipe out almost all the coral on the Great Barrier Reef--a change that could happen within the next 60 years, 

 

Ncoral, no fish, no life.

 

“We've already committed ourselves through the CO2 that we’ve put into the atmosphere to some changes on the Great Barrier Reef. Now what happens to next is really up to us.”

 

And it's not the only effect of global warming. As carbon dioxide levels rise in the atmosphere, acidity⁵ levels rise in the ocean, dissolving the living coral away from the rocks. If it continues, the Great Barrier Reef will perish. We may be the last generation to see this incredible natural wonder as it is today. But the one thing that the past has taught us is that the reef always bounces back. The question is will we be around to see it?

1 astounding   

adj.使人震惊的vt.使震惊，使大吃一惊astound的现在分词)

参考例句：

• There was an astounding 20% increase in sales. 销售量惊人地增加了20%。
• The Chairman's remarks were so astounding that the audience listened to him with bated breath. 主席说的话令人吃惊，所以听众都屏息听他说。 来自《简明英汉词典》

2 mechanism   

n.机械装置；机构，结构

参考例句：

• The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
• The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。

3 algae   

n.水藻，海藻

参考例句：

• Most algae live in water.多数藻类生长在水中。
• Algae grow and spread quickly in the lake.湖中水藻滋蔓。

4 bleaching   

漂白法，漂白

参考例句：

• Moderately weathered rock showed more intense bleaching and fissuring in the feldspars. 中等风化岩石则是指长石有更为强烈的变白现象和裂纹现象。
• Bleaching effects are very strong and show on air photos. 退色效应非常强烈，并且反映在航空象片上。

5 acidity   

n.酸度，酸性

参考例句：

• This plant prefers alkaline soil,though it will readily tolerate some acidity.这种植物在酸性土壤中也能生存，但硷性土壤更加适宜。
• Gastric acidity would not prevent the organism from passing into the gut.胃的酸度不能防止细菌进入肠道。