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(424) / 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(141) / 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(67) / 评论(0) 分类 VOA常速英语2008年(二月)

SCIENCE IN THE NEWS - Anthrax Has Been Widely Feared Since the 2001 Anthrax Attacks in the United BARBARA KLEIN: This is SCIENCE IN THE NEWS, in VOA Special English. Im Barbara Klein. CHRISTOPHER CRUISE: And Im Christopher Cruise. Today we tell about

发表于:2019-01-12 / 阅读(35) / 评论(0) 分类 2011年VOA慢速英语(十一)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(112) / 评论(0) 分类 2015年VOA慢速英语(七)月

AS IT IS 2015-06-05 Anthrax Shipments Incident Continues to Grow 误发活性炭疽菌事件持续增加 The United States military now says it might have sent live anthrax to 52 laboratories in the United States and three other countries. On Wednesd

发表于:2019-01-12 / 阅读(40) / 评论(0) 分类 2015年VOA慢速英语(六)月