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：
60秒科学：Healthy Lung Microbes Keep Mice Breathing Easy
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。
Human cells are outnumbered ten-to-one by the microbes that thrive in and on us. Now a study finds that the tiny organisms living in our lungs may protect us from asthma.
A newborn’s lungs start out sterile and then become colonized by microbes. To see how lung microbes might influence disease susceptibility, researchers studied mice, which also start with sterile lungs that soon host microbes.
In the first two weeks of life, these microbial communities shift and proliferate. So the scientists looked at three groups of mice: babies three days old, 15-day-old mice, and two-month old adults. All were exposed to dust mites, which provoke inflammation.
The newborn mice developed inflamed lungs°™similar to asthma. But the older groups remained mostly inflammation free, indicating a protective role for their lung microbes.
The researchers then exposed older mice whose lungs had been kept sterile to mites. These mice did get inflamed lungs. The study is in the journal Nature Medicine. [Eva S. Gollwitzer et al, Lung microbiota promotes tolerance to allergens in neonates via PD-L1]
The researchers say that early lung colonization by a diverse, protective microbial community appears crucial. They hope to extend these studies to human infants°™to better understand our lung microbes, and help kids breathing freely. (Also see Drugs to Be Derived from Insights into Body-Dwelling Bacteria)
-Cynthia Graber
