PTE考生目前最大的问题之一就是练习题缺乏。除了有限的基本官方书（PLUS，Testbuilder, OG）之外，就没有题了。很多英语基础不是很扎实的同学很难找到练习材料。墨尔本文波雅思PTE培训学校专门为墨尔本，悉尼PTE考生准备了适合PTE听力阅读练习的科学60秒。各位PTE同学可以练习PTE听力中的summarise spoken text和PTE口语中的retell lecture，练习记笔记技巧和复述。废话少说，下面开始：
听力内容：
60秒科学节目（SSS）是科学美国人网站的一套广播栏目，英文名称：Scientific American – 60 Second Science,节目内容以科学报道为主，节目仅一分钟的时间，主要对当今的科学技术新发展作以简明、通俗的介绍，对于科学的发展如何影响人们的生活环境、健康状况及科学技术，提供了大量简明易懂的阐释。
This is Scientific American — 60-Second Science. I’m Christopher Intagliata.
The first life on Earth appeared about four billion years ago. One place these pioneering organisms may have emerged is at hydrothermal vents, deep underwater. Where unusual chemistry providedenergy for primitive life–forms to survive. Life–forms like the methane–belching microbes found at the vents today.
Now, for the first time, researchers have found evidence of methane–producing life insimilarly extreme conditions, but at the surface of the Earth — at a spring in northernCalifornia, called The Cedars. The water there is extremely basic — with a pH of 11.6. And it contains no oxygen. Not an easy place to survive.
Researchers tested water and sediment at the Cedars. Some samples got dosed with mercuricchloride to kill any life present. Those dosed samples produced no methane. But the samples in which microbes were allowed to survive did put out methane. Confirming that at least some of the methane at the springs is indeed biological in origin. The findings appear in the Journal of Geophysical Research: Biogeosciences.
The finding has implications for climate change alleviation. A geologically similar spring in Omanhas been proposed as a site for carbon storage—pumping CO2 underground, where it gets incorporated in stone. But the extremophiles at The Cedars can use CO2 to make methane—an even more potent greenhouse gas. “So imagine pumping CO2 into the ground and having it come back up as methane.” Penny Morrill, a biogeochemist at Memorial University of New foundland. “This will not necessarily happen, but it is something to be tested for before fully implementing a carbon capture and storage technology at one of these types of sites.”
Morrill says the study’s also a reminder that life is tenacious. “We should not let our biases prevent us from looking for evidence of life in what we would otherwise consider an unexpected place.” Including other planets and moons.
Thanks for listening Scientific American – 60-Second Science Science. I’m Christopher Intagliata.
