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Science  12 May 2000:
Vol. 288, Issue 5468, pp. 923
DOI: 10.1126/science.288.5468.923b

What a relief! Take a virtual jaunt across 2.6 billion years of U.S. geological history at this Web version of a stunning new map that combines color geologic zones and detailed topography. Follow links to zoom in on dozens of features—from the ribbon of granite and metamorphic rocks at the bottom of the Grand Canyon, to fingerlike Cape Cod and Long Island, formed by terminal glacial moraines. Or click on a geological timeline to pull up continental maps of rocks from a single period.

Best of biochemistry. Need to review the Krebs cycle or see an amino acid in 3D? This site, which accompanies a biochemistry textbook, offers a terrific list of links ranging from molecular models to online texts, molecular biology quizzes, and enzyme databases.

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