科学家通过采集和分析有数百年历史的珊瑚礁样本发现，气候变化对大堡礁造成了严重威胁。研究表明，过去十年中大堡礁周围的海水温度达到了四百年来的最高点。
The Great Barrier Reef is Earth's largest collection of coral reefs, and it's home to thousands of marine species.
大堡礁是地球上规模最大的珊瑚礁群，这里生活着成千上万种海洋生物。
This alarming new evidence comes from inside the coral itself. Over many years, marine scientists have collected cores – samples drilled out of the skeletons of coral – that provide clues about how the environment in the reef is changing. Corals are animals that can live for centuries, and as they grow, they lay down chemical signals in their bodies that indicate the temperature of the water they're in.
这份令人担忧的新证据来自于珊瑚的内部。多年来，海洋科学家从珊瑚内部钻取了许多核心样本，这些样本提供了大堡礁周围环境变化的证据。珊瑚可以存活数百年之久，它们在不断生长的同时会在身体中留下能反映周遭海水温度的化学信号。
Researchers in Australia re-examined thousands of these cores and cross referenced them with historical sea temperature records. The oldest of the samples they studied dated back 400 years before the Industrial Revolution. This revealed that in the past decade, temperatures around the Great Barrier Reef were the warmest of the last four centuries.
澳大利亚的研究人员重新检查了数千份珊瑚的核心样本，并和海洋温度的历史记录进行了交叉对比。在他们研究的所有样本中，最古老的样本能追溯到工业革命前四百多年。所以这项研究表明，过去十年间大堡礁周围的海水温度处于四个世纪以来的最高点。
Climate change is now driving more extreme and more frequent marine heatwaves that threaten the survival of this ancient reef. The Great Barrier Reef is a UNESCO World Heritage Site, and the scientists hope that this research could persuade the UN organisation to give it official endangered status to send a signal to the world about how grave the problem of global warming is for this vast and threatened wonder of the natural world.
气候变化正驱动着海洋热浪变得更加强烈和频繁，进而威胁这片古老珊瑚礁的生存。大堡礁是一个联合国教科文组织世界遗产地，而科学家们希望这项研究能够说服联合国教科文组织正式将大堡礁的珊瑚列为濒危物种，从而向世界发出讯号：这片自然造就的宏伟奇观正面临全球变暖带来的严峻威胁。
词汇表
coral reefs 珊瑚礁
marine species 海洋生物
alarming 令人担忧的
drilled out 钻取
cross referenced 交叉对比
heatwaves 热浪
threaten 威胁
endangered status 濒危状态
send a signal 发出一个讯号
grave 严峻的
vast 庞大的
wonder 奇观
阅读理解：请在读完上文后，回答下列问题。
1. How do coral cores provide information about past environmental conditions?
2. True or False? Corals are plants.
3. What did re-examining the coral cores and cross referencing them with historical sea temperature records reveal?
4. Why do the scientists hope the Great Barrier Reef will be given official endangered status?
答案
1. How do coral cores provide information about past environmental conditions?
As corals grow, they lay down chemical signals in their bodies that indicate the temperature of the water they're in.
2. True or False? Corals are plants.
False. Corals are animals.
3. What did re-examining the coral cores and cross referencing them with historical sea temperature records reveal?
The study revealed that in the past decade, temperatures around the Great Barrier Reef were the warmest of the last four centuries.
4. Why do the scientists hope the Great Barrier Reef will be given official endangered status?
The scientists hope the Great Barrier Reef will be given official endangered status to send a signal to the world about how grave the problem of global warming is for it.