Bacteria are extremely small living things. While we measure our own sizes in inches or centimeters, bacterial size is measured in microns. One micron is a thousandth of a millimeter: a pinhead is about a millimeter across. Rod-shaped bacteria are u

发表于:2018-11-28 / 阅读(425) / 评论(0) 分类 新概念优美背诵短文50篇

Bacteria are extremely small living things. While we measure our own sizes in inches or centimeters, bacterial size is measured in microns. One micron is a thousandth of a millimeter: a pinhead is abo

发表于:2018-12-01 / 阅读(142) / 评论(0) 分类 新东方背诵文选

By Ruth Reader Washington, DC 13 February 2008 There is growing concern around the world over illnesses caused by new antibiotic-resistant bacteria, or so-called superbugs, and the decreasing effectiveness of antibiotics to treat infections. Earlier

发表于:2019-01-07 / 阅读(69) / 评论(0) 分类 VOA常速英语2008年(二月)

Experts: Let Produce Dry Out to Avoid Bacteria American researchers say farmers should wait one day after a rain storm or watering their fields to harvest fresh fruits and vegetables. They say gathering the crops at least 24 hours after rainfall incr

发表于:2019-01-12 / 阅读(114) / 评论(0) 分类 2015年VOA慢速英语(七)月

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

发表于:2019-01-19 / 阅读(67) / 评论(0) 分类 世界各地新闻集锦

BEIJING, May 24 (Xinhuanet) -- Scientists revealed for the first time the molecular structure of proteins, which enables bacteria to transfer electrical charges, according to a new study. The revelation was published in Proceedings of the National Ac

发表于:2019-02-07 / 阅读(50) / 评论(0) 分类 英语新闻