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。悉尼文波雅思PTE培训学校专门为澳洲，尤其是悉尼、墨尔本的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。
Black Hole Quasar Building Galaxy
A study in the journal Astronomy & Astrophysics finds that a distant quasar, powered by a black hole, is building a galaxy that will eventually surround the black hole. Cynthia Graber reports
Which came first, black holes or galaxies? It’s been a bit of a conundrum for astrophysicists. Black holes are known to devour matter, but did they arise before or after, the galaxies in which they exist? Now, scientists say it looks like the black holes build their own galaxies. The research was published in the journal Astronomy & Astrophysics.
Scientists were checking out a quasar, an incredibly distant, incredibly bright object. This quasar was the only one without a known host galaxy. Researchers thought the galaxy must be hidden behind some dust. But they didn’t find one. What they did find is a nearby galaxy that’s producing stars at a rapid pace—the equivalent of about 350 suns per year, a hundred times faster than typical galaxies.
Scientists observed that the quasar is shooting out highly energetic particles and fast-moving gas in the direction of the galaxy. It looks as if that’s inducing the creation of those stars. So the galaxy will keep growing until it envelops the quasar itself. The researchers conclude that galaxies may thus be formed by clouds of gas that are bombarded by streams of matter and energy from black holes—which are building their own homes.
—Cynthia Graber
