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，PTE听力口语-科学60秒-Frosty Moss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。
Quitting smoking is tough, so tough that only about 5 percent of smokers who try to quit in a given year actually succeed.
Medications can double those odds—which still leaves a high failure rate.
And a promising vaccine, meant to arouse an immune response to nicotine, could notbeat a placebo in clinical trials.
But researchers haven’t given up on a vaccine yet.
Instead of revving up the immune system, though, they’ve come up with a new idea:why notuse an enzyme to break down nicotine—before it gives you a buzz?
“For almost 50 years there’s been reports of bacteria that can actually use nicotine to thriveon.”
Kim Janda, a chemist and immunologist at The Scripps Research Institute.
“The bacteria uses nicotine as its sole source of carbon and nitrogen.”
It does the trick with a nicotine–chomping enzyme.
So Janda and his colleagues added the enzyme to mouse serum, doped with a cigarette’sworth of nicotine.
The enzyme was stable at human body temperature,and was able to cut the half–life ofnicotine from a couple hours to less than 15 minutes that is, it greatly accelerated nicotine’sdisappearance.
The study is in the Journal of the American Chemical Society.
But Janda says the enzyme isn’t ready for prime time yet.
It’s bacterial—so “you’re going to get an immune response, immune surveillance from it.”
And right now, the other important half–life, that of the enzyme in serum, is only 3 days.
So it won’t stick around long enough to be an effective vaccine. ”
A month would be great, a week or two would also be reasonable.”
While the researchers work out the kinks, smokers will have to rely on the tried–and–truemethods of quitting:counseling, medication or good old cold turkey.
