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:
Rule Governs Mammal Micturition
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。
In the time it takes you to listen to this story, an elephant could empty its bladder about three times. And, despite being much smaller, so could an adult cat. And a goat. Also a cow. Because researchers find that all mammals that weigh more than six-and-a-half pounds or so take about the same time to pee: 21 seconds, plus or minus 13 seconds.
The researchers videoed various mammals urinating at Zoo Atlanta. And they found that, once you get above the squirrel-mouse-shrew level, tinkle-time does not scale with body size. Good news for elephants, who could otherwise spend all day going number one.
Seems that larger animals have a longer urethra, the conduit that whisks the wee-wee away. That difference in size is big enough that gravity starts to really weigh in. As a result, when Jumbo answers nature’s call he has a much faster flow than does Mittens.
Given the urethra’s structure, the researchers say that the mammalian urinary system can be “scaled up by a factor of 3,600 in volume without compromising its function.” The study is in the Proceedings of the National Academy of Sciences. [Patricia J. Yang et al, Duration of urination does not change with body size, preprint]
This hydrodynamic finding could help engineers design systems that rapidly drain reservoirs, regardless of size. It also means if Mittens and Jumbo hit the head together, they can come out at the same time.
—Karen Hopkin