英语翻译For the past 50 years,scientists have scoured the skies

英语翻译
For the past 50 years,scientists have scoured the skies for radio signals from beyond our planet,hoping for some sign of extraterrestrial life.But one physicist says there's no reason alien life couldn't already be existing among us—or maybe even in us.
Paul Davies,an award-winning Arizona State University physicist known for his popular science writing said Tuesday that life may have developed on Earth not once but several times.
Davies said the variant life forms - most likely tiny microbes—could still be hanging around "right under our noses - or even in our noses."
"How do we know all life on earth descended from a single origin?" he told a conference at London's prestigious Royal Society,which serves as Britain's academy of sciences."We've just scratched the surface of the microbial world."
Unusual organisms abound - including chemical-eating bacteria which hide out deep in the ocean and organisms that thrive in boiling-hot springs—but that doesn't mean they're different life forms entirely.
"How weird do they have to be suggested a second genesis as opposed to just an obscure branch of the family tree?" he said Cooling fan.Davies suggested that the only way to prove an organism wasn't "life as we know it" was if it were built using exotic elements which no other form of life had.
Such organisms have yet to be found.Davies also noted that less than 1 percent of all the world's bacteria had been comprehensively studied Chi iron leaving plenty of time to find unusual organisms.

我自己翻译的 看着还行呢 就把分给我吧
在过去的50年里,科学家们寻遍地外的无线电信号,希望发现外星生命的迹象.但一位物理学家说,没有理由否认地外生命已经来到我们身边,甚至可能在人群中.
一个屡获殊荣,以写科普文章著名的亚利桑那州立大学物理学家保罗·戴维斯在周二说,地球上的生命不止出现一次,可能已经好几次了.
戴维斯说,生命变体形式,最有可能是极小的微生物,可能仍然出没于“在我们的眼皮底下,甚至在我们的鼻子里” .
“我们怎么知道地球上所有生命只有一个单一的起源?”他在伦敦著名的皇家科学院（相当于英国科学院）上的一次会议上说,“我们刚刚触及到地球表面的微生物世界.”
有很多不寻常的生物,包括藏在海洋深处的化学吞噬细菌,在沸腾的温泉里茁壮成长的生物体,但是,这并不意味着它们是完全不同的生命形式.
“很奇怪他们必须要提出一个第二起源以此反对晦涩的分支树理论?”戴维斯指出,只有一种方法才能证明一个生物体不是我们所谓的生命就是这个生命体是不是有别的生命没有的元素组成.
这种生物尚未被发现.戴维斯还指出,只有不到世界上所有的细菌百分之一得到了深入研究,这样留下足够的时间来寻找不同寻常的生物.