(单词翻译:单击)
听力文本
California continues to suffer under a historic drought. The state has received very little rainfall over the past four years.
California is famous for its huge sequoia trees. They are among the largest and oldest living things on Earth. But scientists say the trees are suffering because of the lack of water.
Now the National Park Service is studying how the drought has affected the sequoias and what can be done to help them survive.
Anthony Ambrose is a tree biologist with the University of California, Berkeley. One recent day, he slowly climbed up a giant sequoia in California's Sierra Nevada Mountains. The Sierra Nevada range is the only place on earth where sequoias live.
"It's an amazing experience to be able to climb up into these things and know that it's been growing in this same spot for you know a thousand years or more."
Sequoias can grow to a height of over 90 meters tall. The bottom of the tree can be up to 15 meters wide. Some trees are more than 3,000 years old.
The Sierra Nevada range once had plenty of water because of mountain streams. But less water is available now because of the drought. Each sequoia needs more than 3,000 liters of water a day. The trees are now getting much less. Some of them are showing signs of thirst, says Anthony Ambrose.
"We've observed some unusual and abnormal levels of foliage die-back, which haven't been observed in the park before."
Researchers are using scientific equipment in tree canopies to help measure air temperature and humidity levels. They also are studying sequoia seedlings, information from individual trees and images collected by aircraft to measure the seriousness of the danger.
One possible solution would be to cut down less important tree species because other plants compete with the sequoias for water. Koren Nydick of the National Park Service is one of the scientific investigators.
"They'll have more water than they would have in a denser forest, more nutrients and light and therefore be more resistant and resilient to these hot droughts they're faced with in the future."
Scientists say that over thousands of years, sequoias have survived many droughts, forest fires, insect infestations and other disasters. Scientists say the sequoias will probably survive this drought, unlike many other California trees.
I'm Marsha James.
词汇学习
1.historic adj.在历史上重要的，有历史影响的
The groups had historic scores to settle with each other.
这两个集团之间有几笔旧账要了结。
2.amazing adj.令人惊异的
The most amazing thing about nature is its infinite variety.
大自然最让人惊叹的是它的无限多样性。
3.spot n.地点，场所
A sudden break in the cloud allowed rescuers to spot Michael Benson.
天气的突然放晴帮助救援人员找到了迈克尔·本森。
4.observe vt.& vi.观察；研究
Scientists observe the same dynamics in fluids.
科学家们在液体中观察到了同样的驱动力。
5.collect vt.收集；收藏
He was grateful for a chance to relax and collect his thoughts.
他很庆幸有机会放松放松，整理一下自己的思绪。
6.resilient adj.能复原的；弹回的
George Fraser was clearly a good soldier, calm and resilient.
乔治·弗雷泽显然是个好士兵，沉着冷静且适应力强。
内容解析
1.One recent day, he slowly climbed up a giant sequoia in California's Sierra Nevada Mountains.
climb up向上爬，攀登
Who would have expected that he could climb up that steep cliff?
这么陡的峭壁,谁知他竟爬上去了。
2.The Sierra Nevada range once had plenty of water because of mountain streams.
plenty of很多，大量的
She is in the fortunate position of having plenty of choice.
好在她有很多选择。
3.One possible solution would be to cut down less important tree species because other plants compete with the sequoias for water.
cut down砍倒
A vandal with a chainsaw cut down a tree.
一个故意破坏公物的人用链锯伐倒了一棵树。
参考翻译
加利福尼亚继续遭遇历史性的干旱。过去四年，该州的降雨量一直非常少。
加利福尼亚州以巨大的红杉树著称。它们是地球上最大，最古老的生物之一。但是科学家表示，由于缺水，这些树木也受到影响。
现在，国家公园管理局正在研究干旱对红杉树造成了什么样的影响，应该怎样帮助它们生存下去。
Anthony Ambrose是加州大学伯克利分校的树木生物学家。最近一天，他慢慢地爬上加利福尼亚内华达山脉一棵巨大的红杉树上。
“能够爬上这样的大树是一次非常独特的体验，据我们所知，这棵树已经在这里生长了至少1000年。”
红杉树能长到90多米高。树木底部直径可以达到15米。一些树木已经有3000多年的历史。
由于山间溪流，内华达山脉原本有足够的水。但是由于干旱，这里的水源减少。每棵红杉树每天吸收超过3000升的水。而现在吸收的水量少得多。其中一些树木已经表现出饥渴的症状。
“我们已经观察到了一些不正常的树枝枯梢现象，这在之前是没有遇见过的。”
研究人员在树冠上安装了科学仪器来测量空气温度和湿度水平。他们还研究了红杉树幼苗，来自每一株树木的信息以及飞机收集的图片信息，衡量风险程度。
其中一个可能的解决方法是砍伐不那么重要的树种，因为其他树木与红杉树竞争水资源。国家公园管理局的Koren Nydick是其中一位科学调查人员。
“它们将获得比在茂密的森林中更多的水，更多的养料和阳光，因此将来面对炎热干旱将更有抵抗力。”
科学家表示，数千年来，红杉木经历了多次干旱，森林大火，害虫感染和其他灾难。科学家表示，与加利福尼亚其他树木不同，红杉木应该能够度过这次干旱。
我是Marsha James。
