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：
Laser Zap Determines Fruit Ripeness
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。
Ever throw an avocado in a paper bag with a banana to get the avocado to ripen faster? That trick works because both of them are what’s called “climacteric” fruits. Meaning they release ethylene gas as they mature°™and the gas in turn accelerates ripening. At maximum ethylene release, the fruit reaches peak ripeness: ideal taste and texture. After that, the fruit’s cells begin to die, molds move in, and it rots.
So how to determine the best time for picking°™and eating? Today’s high-tech farmers might sample the ethylene released by the fruit, as it sits in an airtight container. Or use a color meter, to track a fruit’s progression towards “ripe color.”
But now researchers have devised what might be a simpler and more scientifically accurate technique°™shooting fruit with lasers. When they zapped golden delicious apples, what bounced back was a speckled pattern of black and red dots: a measure of how the fruit’s cells and water absorbed and reflected the laser light. That pattern changed over time, right in step with the fruit’s release of ethylene. Meaning these images could be a good proxy for ethylene measurements, and let farmers know the best time to harvest. The study is in the journal Applied Optics. [Rana Nassif et al, Detection of Golden apples’ climacteric peak by laser biospeckle measurements]
Next, the researchers hope to develop a handheld laser for farmers, so they can shoot fruit right on the tree. It remains to be seen if laser measurement of bananas will have°≠appeal.
–Christopher Intagliata
