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Welcome to the USGS - U.S. Geological Survey
Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment.
点击进入 - 2014-02-04 - 收藏
Library of Congress
The Library of Congress. The Library of Congress is the nation\'s oldest federal cultural institution, and it serves as the research arm of Congress. It is also the largest library in the world, with more than 120 million items. The collections include books, sound recordings, motion pictures, photographs, maps, and manuscripts
点击进入 - 2015-03-20 - 收藏
American Society for Microbiology
The American Society for Microbiology (ASM) is the oldest and largest single life science membership organization in the world. Membership has grown from 59 scientists in 1899 to more than 39,000 members today, with more than one third located outside the United States. The members represent 26 disciplines of microbiological specialization plus a division for microbiology educators.美国微生物学会（American Society for Microbiology，简称ASM），是生命科学领域中全球最大且历史最悠久的会员组织。会员人数从1899年的59名已发展到现今超过43000名，其中超过三分之一的会员来自
点击进入 - 2013-10-22 - 收藏
Bureau of Reclamation Homepage
Bureau of Reclamation Homepage www.usbr.gov Department of the Interior, Bureau of Reclamation Homepage, Water, Dams, Dam, Projects & Facilities, Hydromet, Agrimet, hydropower
点击进入 - 2014-02-04 - 收藏
Coursera公开课
Coursera We just released an internationalized version of Coursera. If you want to switch back to English, please set your Language.... www.coursera.org
点击进入 - 2013-11-17 - 收藏
U.S. Department of State
U.S. Department of State Department Of State. The Office of Electronic Information, Bureau of Public Affairs
点击进入 - 2014-02-04 - 收藏
ACS Publications
ACS Publications manages the scholarly publishing program of the world’s largest and most influential scientific society. Every year over 100,000 authors and their research teams from the community of scientists worldwide submit their work for consideration, review, and publication to ACS Publications.
点击进入 - 2015-03-22 - 收藏
Amazon.com
Online shopping from the earth's biggest selection of books, magazines, music, DVDs, videos, electronics, computers, software, apparel & accessories, shoes, jewelry, tools & hardware, housewares, furniture, sporting goods, beauty & personal care, broadband & dsl, gourmet food & just about anything else.
点击进入 - 2014-02-04 - 收藏