2-甲胺乙醇

This is Scientific Americans 60-Second Science. Im Cynthia Graber. This will just take a minute. Saliva contains many useful components: lubricants, enzymes for breaking down food and now compounds that can reveal a persons age. Thats according to a

发表于:2018-12-24 / 阅读(64) / 评论(0) 分类 Scientific American(六)月

This is Scientific American's 60-Second Science. I'm Karen Hopkin. This will just take a minute. As Valentines day approaches, remember, its the thought that counts. Just ask a decorated cricket. Because according to a study published in the January

发表于:2018-12-24 / 阅读(59) / 评论(0) 分类 Scientific American(一)月

AGRICULTURE REPORT - Restrictions on Methyl Bromide By Mario Ritter Broadcast: Tuesday, March 16, 2004 This is Steve Ember with the VOA Special English Agriculture Report. Graphic Image Some chemicals

发表于:2019-01-06 / 阅读(88) / 评论(0) 分类 农业与发展

By Greg Flakus Houston 16 October 2007 In recent months food costs in the United States have gone up by well over six percent and some economists see government-mandated use of bio-fuels as a key reason. But, as VOA's Greg Flakus reports from Houston

发表于:2019-01-25 / 阅读(49) / 评论(0) 分类 2007年VOA常速英语(十月)

Science and Technology Epigenetics and stress Baby blues 科技 外因遗传与压力 新生儿蓝调曲 A mother's stress while she is pregnant can have a long-lasting effect on her children's genes 母亲孕期压力过大会对孩子的基因造成长

发表于:2019-01-26 / 阅读(58) / 评论(0) 分类 经济学人科技系列

By Jeffrey Young Washington 16 October 2007 U.S. farmers have gone through many cycles of boom and bust. But as VOA's Jeffrey Young reports, prospects for American agriculture are looking up, thanks to rising crop prices and land values, especially i

发表于:2019-02-03 / 阅读(53) / 评论(0) 分类 2007年VOA常速英语(十月)