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：
Bigger Brains Come at a Cost
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。
Guppies bred for larger brains also had smaller guts and produced fewer offspring. Sophie Bushwick reports
Comparisons of different animals have shown that larger brains provide greater intelligence, but they also guzzle more energy and have other consequences. Now scientists have observed the effects of varying brain size within a single species: guppies. The work is in Current Biology. [Alexander Kotrschal et al., Artificial Selection on Relative Brain Size in the Guppy Reveals Costs and Benefits of Evolving a Larger Brain]
Swedish researchers bred two different lines of guppies, selecting one for larger brains and one for smaller. The fish quickly modified until brains were nine percent larger in the big-brained line than in the other.
Not surprisingly, when 48 guppies were given learning tests, large-brained female fish outperformed small-brained females. However, males from both lines scored about the same, possibly because the female guppies’ visual system was more suited to the type of intelligence test used.
But big brains also had a downside—the brainier fish had smaller guts, by 20 percent for males and 8 percent for females. Plus, the large-brained guppies produced 19 percent fewer offspring. In order to provide energy to their bigger brains, the egghead fish made sacrifices that may be evolutionary disadvantages. It may indeed be possible to be too smart for your own good.
—Sophie Bushwick
