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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
Scientific American(六)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
农业与发展
Protamine sulfate is a drug that reverses the anticoagulant effects of liver compounds such as heparin. Protamine is extracted from the sperm of salmon and other species of fish, and then made into a protamine sulfate injection which is a necessary d
世界各地新闻集锦
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
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
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
2007年VOA常速英语（十月）