在美国黄石国家公园,曾经栖息着土生土长的狼群,直到有一天,狩猎者将它们驱逐殆尽。然而到了 1995 年,(由于一个激进的管理项目)狼群开始重新回归,一些有趣的现象出现了:黄石国

发表于:2018-12-09 / 阅读(158) / 评论(0) 分类 TED公开课:生态谜云

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发表于:2018-12-11 / 阅读(55) / 评论(0) 分类 新编大学英语阅读部分

this--这个 these--这些 those--那些 that--那个 than--比较

发表于:2018-12-16 / 阅读(44) / 评论(0) 分类 用听的背单词-基础2000MP3(h-z)

This is Scientific American's 60-Second Science. I'm Cynthia Graber. This'll just take a minute. The Patriot Act and the Bioterrorism Preparedness Act were passed in 2001 and 2002. These laws in part cover research on pathogens and toxins thought to

发表于:2019-01-08 / 阅读(62) / 评论(0) 分类 Scientific American(五)月

1. Federal agents expect to be at this Detroit-area horse farm for several weeks to search for clues to Jimmy Hoffa's disappearance. The former Teamsters leader vanished in 1975. 2. The general tap pe

发表于:2019-01-08 / 阅读(133) / 评论(0) 分类 美联社新闻一分钟2006

Annie Leibovitz Takes New Path in 'Pilgrimage' There are homes and personal items that belonged to people who are no longer with us, including artists, scientists, photographers, and a U.S. president. Leibovitz says she went on a journey from 2009 to

发表于:2019-02-07 / 阅读(36) / 评论(0) 分类 VOA标准英语2012年(二月)