Alien Invasion Unlikely
外星人入侵不太可能
Should we fear an invasion from outer space?
我们应该担心外太空入侵吗？
Researchers have been searching and listening for life on other planets. They say we should not be concerned about alien beings any time soon.
研究人员一直在寻找和聆听其它星球上的生命。他们说，我们短期内不用担心外星人。
Michael Garrett teaches at the University of Leiden. He is also the General and Scientific Director of the Netherlands Institute for Radio Astronomy.
迈克尔·加勒特（Michael Garrett）任教于莱顿大学。他也是荷兰射电天文研究所的秘书长和科学总监。
Professor Garrett has been listening for radio signals from other planets, searching for signs of extraterrestrial life. He says advanced civilizations are either rare or do not exist in the areas of outer space he has examined. He adds that natural processes are most likely responsible for any radio signals that have been received on Earth.
加勒特教授一直在聆听来自其它星球的无线电信号，寻找外星生命的迹象。他说，在他已经查验过的外太空领域，先进文明要么很罕见要么不存在。他补充说，最可能对地球上已经接收到的信号负责的是自然现象。
He says that means "we can all sleep safely in our beds tonight. An alien invasion doesn't seem at all likely."
他说，这意味着“今晚我们都可以在床上安心入睡，外星人入侵几无可能。”
Researchers: Love, Evolution Linked
研究：爱情和进化有关联
German researchers say they have discovered that some birds, like humans, can be choosy when deciding on a possible mate.
德国研究人员表示，他们已经发现一些鸟类和人类一样在选择伴侣时很挑剔。
The researchers work at the Max Planck Institute for Ornithology. They performed experiments with Zebra Finch. They let groups of 20 female Zebra Finches freely choose their mate from among 20 males.
这些研究人员在德国马普鸟类研究所工作。他们对斑胸草雀进行了实验。他们让20只雌性斑胸草雀从20只雄性斑胸草雀中自由挑选自己的伴侣。
Half of the resulting pairs were permitted to produce baby birds. The researchers split up the other couples and gave them a mate that the birds had not chosen themselves.
由此产生的鸟类情侣一半被允许生育幼鸟。研究人员把另一半鸟类情侣分开，给它们搭配了一只并非它们自己选择的雄鸟。
The study found that the finch couples that chose one another produced many more babies than those that were forced together.
研究发现，互相选择的雀鸟夫妇比被迫在一起的那些雀鸟生育了更多的幼鸟。
Smokers Have Higher Risk of Losing Teeth
吸烟者牙齿脱落风险更高
There are many good reasons not to smoke tobacco. Researchers have added another: Smokers have a higher risk of losing their teeth than non-smokers.
世界上有很多不吸烟的好理由。研究人员又增加了另一条：和不吸烟者相比，吸烟者牙齿脱落的几率更高。
A new study shows that men who smoke are up to 3.6 times more likely to lose their teeth than men who do not smoke. Women are 2.5 times more likely to lose their teeth than women who don't smoke. The Journal of Dental Research published the findings.
一项新的研究表明吸烟男子牙齿脱落的几率是不吸烟男子的3.6倍以上，在女性中是2.5倍。牙科研究杂志发表了这一调查结果。
Thomas Dietrich was the main writer of the report. He is a professor at the University of Birmingham in England. He says most people lose their teeth from either tooth decay or gum disease, both of which can be caused by smoking.
托马斯·迪特里希（Thomas Dietrich）是该报告的主要撰稿人。他是英格兰伯明翰大学的教授。他说，大多数人牙齿脱落要么是因为蛀牙要么是因为牙龈疾病，这两者都能由吸烟引起。
Because smoking can also hide gum disease, smokers may not know about the poor health of their mouths until it is too late and they start losing teeth.
由于吸烟还会掩盖牙龈疾病，吸烟者可能不知道他们口腔健康状况不佳，直到为时已晚，他们开始牙齿脱落。
The study found that it is not only older people who lose their teeth. Researchers discovered that the connection between smoking and tooth loss was stronger among younger people than those who were older.
研究发现，并非只有老年人牙齿脱落。研究人员发现，吸烟和牙齿脱落之间的关联性在年轻人中比老年人体现得更明显。