In science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produc

发表于:2018-12-01 / 阅读(149) / 评论(0) 分类 新东方现代文背诵篇章

Part I A. key words:invent vocabulary:fax/ calendar/ puppet Mercedes-Benz 1.People in England made the first computer. It was built in 1943. It was made to help England understand secret messages during World War two. 2.Someone in Australia invented

发表于:2018-12-03 / 阅读(58) / 评论(0) 分类 Step by Step2000

By Leta Hong Fincher Washington 29 November 2007 A team of U.S. and British researchers have unveiled a new map of Antarctica that they say will revolutionize research on the frozen continent and contribute to a deeper understanding of climate change

发表于:2018-12-08 / 阅读(59) / 评论(0) 分类 VOA常速英语2007年(十一月)

Scientists have created a climate model that they say proves human activity is responsible for global warming not only at the North Pole, but at the South Pole as well. The model includes data from Antarctica about which relatively little is known.

发表于:2018-12-08 / 阅读(46) / 评论(0) 分类 VOA标准英语2008年(十月)

27. Scientific Theories In science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of thi

发表于:2018-12-08 / 阅读(346) / 评论(0) 分类 新概念优美背诵短文50篇

By Jessica Berman Washington 03 August 2007 There's a period in the development of toddlers when they seem to learn a new word every day. There are different theories about why young children undergo what experts call a word spurt. But one psychologi

发表于:2019-01-07 / 阅读(104) / 评论(0) 分类 2007年VOA标准英语(八月)

Scientists at the Whitehead Institute in Cambridge, Massachusetts say it's fortunate for humans that the Y chromosome is not on the verge of extinction. That's because the Y is the chromosome that makes males males. The outlook is less favorable for

发表于:2019-01-08 / 阅读(289) / 评论(0) 分类 2005年NPR美国国家公共电台

By Mandy Clark London 27 November 2007 A gathering of scientists, artists and engineers met recently in London to discuss ways of helping Africa deal with the effects of global warming. VOA's Mandy Clark reports from London. The message of climate ch

发表于:2019-01-08 / 阅读(57) / 评论(0) 分类 VOA常速英语2007年(十一月)

By Melinda Smith Washington 09 August 2007 The World Health Organization says a mother's milk is the perfect food for a newborn baby. But worldwide statistics show that breastfeeding is frequently abandoned right after birth. VOA's Melinda Smith ha

发表于:2019-01-11 / 阅读(84) / 评论(0) 分类 2007年VOA标准英语(八月)

By Deborah Block Washington, DC 24 January 2006 watch Bird Flu Database report A computer database in the United States is helping researchers find a human vaccine for the bird flu virus -- a disease

发表于:2019-01-13 / 阅读(154) / 评论(0) 分类 2006年VOA标准英语(一月)

By Jessica Berman Washington 10 April 2008 An international team of scientists has conducted an exhaustive survey of Madagascar's thousands of endangered plant and animal species. The information will be used to protect the creatures and vegetation t

发表于:2019-01-31 / 阅读(57) / 评论(0) 分类 VOA常速英语2008年(四月)

By VOA News 20 November 2007 Two separate teams of scientists say they have transformed ordinary human skin cells into ones that look and act like embryonic stem cells. Laboratory teams at universities in the United States and Japan Tuesday announced

发表于:2019-01-31 / 阅读(52) / 评论(0) 分类 VOA常速英语2007年(十一月)

By Jessica Berman Washington 03 April 2008 Three independent teams of researchers have found genes that may explain why some smokers get cancer and others do not, and why some people who never smoke also get the disease. Investigators say the discove

发表于:2019-01-31 / 阅读(48) / 评论(0) 分类 VOA常速英语2008年(四月)

By Chad Bouchard Bali 06 December 2007 More than 200 of the world's leading climate scientists signed a petition calling for negotiators in Bali's United Nations Climate Change Conference to set aggressive targets for reducing greenhouse gas emission

发表于:2019-02-03 / 阅读(62) / 评论(0) 分类 VOA常速英语2007年(十二月)

By Melinda Smith Washington 08 August 2007 Scientists are concerned about the health risks of an ingredient in many of the plastic containers used for food and drinks Bisphenol A or BPA is a common chemical used to make tough, shatter-resistant plast

发表于:2019-02-03 / 阅读(91) / 评论(0) 分类 2007年VOA标准英语(八月)

The Justice Department has shed some light on the evidence it has against the prime suspect in the deadly 2001 anthrax attacks, a U.S. Army scientist who killed himself last week. At a news conference Wednesday, U.S. officials said the scientist, Br

发表于:2019-02-03 / 阅读(72) / 评论(0) 分类 VOA标准英语2008年(八月)

By Jessica Berman Washington 20 September 2007 Scientists say they have evidence that a ferocious dinosaur made famous by the movie Jurassic Park definitely had feathers. Experts say the dinosaur, called Velociraptor, had a wing structure just like m

发表于:2019-02-06 / 阅读(112) / 评论(0) 分类 2007年VOA标准英语(九月)

Maryland, south of Washington, DC 15 October 2007 Scientists are predicting there could be a global food crisis in this century if climate change continues unabated. VOA's Jeff Swicord reports. Buddy Hanse has been farming on land south of Washington

发表于:2019-02-06 / 阅读(68) / 评论(0) 分类 2007年VOA常速英语(十月)

By Jessica Berman Washington 13 February 2008 Scientists in the United States say they have developed fabrics that can generate electricity. Researchers say they have harvested enough electricity to power small electronic devices such as an mp3 playe

发表于:2019-02-08 / 阅读(72) / 评论(0) 分类 VOA常速英语2008年(二月)

The Large Hadron Collider, the world's most powerful atom smasher, has gotten under way. Physicists at the European Organization for Nuclear Research, CERN, in Geneva successfully injected the first beam of particles into this colossal multi-billion

发表于:2019-02-11 / 阅读(81) / 评论(0) 分类 VOA标准英语2008年(九月)