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，练习记笔记技巧和复述。
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’mChristopher Intagliata.
You can thank your parents for your DNA. Becausehumans share genes through sexual reproduction, passing DNA from parent to child. It’s known as the’vertical transfer’ of DNA.
Now imagine if you could share just one or two bitsof your DNA with an unrelated stranger, through a handshake, or other incidental contact—and that stranger inserted your DNA into their genome. No sex. No offspring either. That’scalled the ‘horizontal transfer’ of DNA. It’s obviously not how humans do it. But it’s a mainstayof single-celled organisms like bacteria, which use the process to share antibiotic resistancegenes, for example.
And now French scientists have found that horizontal DNA transfer could be a lot morecommon than we thought in multicellular organisms, too—insects, in this case. Because byanalyzing 195 insect genomes, they found more than 2,200 cases of horizontal DNA transferbetween unrelated species of flies and butterflies, beetles and wasps.
That total quadruples the number of horizontal DNA transfers previously described in allplants, animals and fungi. The study is in the Proceedings of the National Academy of Sciences.
How exactly this genetic transfer happens is still a mystery. Might be viruses, or parasites, doing the DNA delivery. But whatever the cause, it suggests that the evolution of insects, ona molecular level at least, may be something more of a shared success story.
Thanks for listening for Scientific American — 60-Second Science Science. I’m ChristopherIntagliata.