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：
60秒科学：Dark Matter Shell Saved Wannabe Galaxy
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。
Dark matter is that mysterious stuff that apparently accounts for some quarter of the mass and energy in the universe. And for one small wannabe-galaxy, dark matter may have been a lifesaver.
It’s called the Smith Cloud. Astronomers think it’s a failed dwarf galaxy that lacked the requisite mass to produce stars. Many millions of years ago the cloud seems to have collided with the Milky Way and passed through the disk of our galaxy. A new computer simulation finds that the cloud should have been ripped to shreds. That it survived is evidence that it’s protected—by a shell of dark matter.
The report will appear in the journal Monthly Notices of the Royal Astronomical Society. [Matthew Nichols et al, The Smith Cloud and its dark matter halo: Survival of a Galactic disc passage]
That dark matter shell could have insulated the Smith Cloud from the Milky Way’s gravitational forces, which otherwise should have torn Smith apart.
As if its first fender-bender with the Milky Way wasn’t enough, the Smith Cloud is coming back for more. It’s on course to slam into our galaxy again—in about 30 million years. Perhaps future astronomers will note whether its dark matter shroud once again saves the cloud.