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：Bats Jam Rivals’ Sonar to Steal a Meal
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。
Many bats hunt at night—and use echolocation, or sonar, to zero in on their prey. [echolocation clip] That’s slowed down 20 times, so you can hear it. But some insects, like the tiger moth, have figured out how to evade that echolocation—by jamming it. “It makes these ultrasonic clicks in the last moment before it would normally be captured by a bat. [clicking sound] And this interferes with the bat’s echolocation, causing that bat to miss.”
Aaron Corcoran, a postdoc at Wake Forest University. Corcoran studied that phenomenon, and says he’s now discovered that the jamming strategy isn’t limited to prey. Bats do it, too—to foil each others’ hunting efforts.
Corcoran and his colleagues recorded Mexican free-tailed bats, Tadarida brasiliensis, echolocating in the wild. And they happened to pick up a sound bats made only when other bats were hunting. [jamming clip] It reminded them of the moth jamming call. So they played back that sound to bats hunting tethered moths, in a field experiment. And sure enough—bats who heard the bat jamming call while echolocating, were 70 percent less successful at capturing the tethered moth, than bats who heard a generic tone, [tone clip] or no sound at all. The study is in the journal Science. [Aaron J. Corcoran and William E. Conner: Bats jamming bats: Food competition through sonar interference]
Of course, if you have a porch light you may be wondering: aren’t there more than enough moths to go around? But here’s the thing. “The Mexican free-tailed bat has the largest colonies of any mammal on the planet except for humans—with up to a million individuals. So yeah, there’s a lot of insects out there but there’s a lot of bats to compete with, so they have to find ways to one-up each other basically.” Tricky. A real fly-by-night operation.
—Christopher Intagliata
