Of the many puzzles mathematicians ponder, one is new ways to tie knots. There are more than six billion different types of knots that have been tabulated by mathematicians. Six billion. David Leigh, a chemist at the University of Manchester in the U

发表于:2018-12-24 / 阅读(51) / 评论(0) 分类 2017年Scientific American(一)月

Many people who have an accident and break their back, never walk again. Your spinal cord is inside your backbone. It sends messages to your brain. It is part of your nervous system which controls your movements. In New Zealand, we have about one new

发表于:2018-12-31 / 阅读(83) / 评论(0) 分类 新西兰英语

Larry和李华今天去给他们的朋友Jim买结婚礼物。Jim下个周末就要结婚。今天李华会学到两个常用语:to tie the knot和drop-dead gorgeous. LL: I can't believe Jim is goin

发表于:2019-02-01 / 阅读(56) / 评论(0) 分类 美国之音《流行美语》

WASHINGTON, Nov. 11 (Xinhua) -- The U.S. Food and Drug Administration (FDA) on Friday approved HEMACORD, the first licensed hematopoietic progenitor cells-cord cell therapy. HEMACORD is indicated for use in hematopoietic stem cell transplantation pro

发表于:2019-02-03 / 阅读(111) / 评论(0) 分类 英语新闻

By Robert Raffaele Washington 06 May 2008 Medical researchers say a simple decision by expectant mothers can mean the difference between life and death for thousands of people. Blood from umbilical cords has been used in life-saving transplants for p

发表于:2019-02-06 / 阅读(56) / 评论(0) 分类 VOA标准英语2008年(五月)

Voice 1 Hello. Im Mike Procter Voice 2 And Im Marina Santee. Welcome to Spotlight. This programme uses a special English method of broadcasting. It is easier for people to understand, no matter where in the world they live. Voice 2 The sound of new l

发表于:2019-03-04 / 阅读(109) / 评论(0) 分类 环球英语 Spotlight