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。悉尼文波雅思PTE培训学校专门为澳洲，尤其是悉尼、墨尔本的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，PTE听力口语-科学60秒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。
When you hear the word “mutation,” you may think of something destructive, or of Marvel’s X-Men. But some mutations—which are just differences in DNA—can be historic. Take, for example, a genetic sequence found in the vast majority of people from Tibet.
Millions of Tibetans spend their days at average elevations of nearly 15,000 feet—that’s more than half the height of Mount Everest. Up there, the air is thin—with 40 percent less oxygen than at sea level. That lack of O2 would leave most Westerners struggling for breath, but Tibetans seem to breathe easy.
To find out how these highlanders cope, researchers compared the DNA of 90 Tibetans to that of people who are not altitude adapted. And they discovered a single change that prevents Tibetans’ blood from becoming dangerously clogged with red blood cells—a response that can be deadly for non-native mountaineers. The finding is described in the journal Nature Genetics.
This mutation appears to have originated just 8,000 years ago. But it’s so advantageous that today nearly 90 percent of Tibetans have it. While it’s virtually absent in even closely related lowland neighbors.
The finding demonstrates that a really useful mutation will always rise to the top.
