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：
Goo Keeps Bones Strong but Supple
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。
New news is goo news when it’s inside our bones, anyway. Because a combination of imaging techniques and modeling has revealed that our bones are filled with a natural chemical goo that’s key to the bones’ function as support structures. The finding is in the Proceedings of the National Academy of Sciences. [Erika Davie et al, Citrate bridges between mineral platelets in bone]
And it could inform research into the prevention and treatment of osteoporosis.
Bone actually largely consists of tiny crystals of calcium phosphate, and the goo is in fact a combination of the compound citrate and water. The viscous mixture surrounds the crystals, letting them slide and slip past each other.
The resulting flexibility lets bones bend but not break under normal pressure. Most of that flexibility had been attributed to the presence of the protein collagen, but the citrate goo appears to play a big role too.
Unfortunately, as people age, the goo may begin to seep out. The remaining mineral crystals then can fuse together, according to lead researcher Melinda Duer at the University of Cambridge, and the bones become brittle.
Keeping the goo in its proper place between the mineral crystals might thus help ward off osteoporosis. Which would be a bona fide breakthrough.
－Dina Fine Maron