单词：cement water ratio
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Broadcast: August 4, 2003 This is Bill White with the VOA Special English Development Report. Safe drinking water has always been rare and valuable. Throughout the world, drinking water has to be stor
VOA2003（下）-发展与科学
DEVELOPMENT REPORT – January 7, 2002: Storing Drinking Water By Gary Garriott This is the VOA Special English Development Report. Safe drinking water has always been rare and valuable. Throughout th
农业与发展
This is Scientific American's 60-Second Science. I'm John Matson. Got a minute? Earth's surface is dominated by oceans. But where did all that water come from? Asteroids and comets smashing into the early Earth have long been thought to be a promisin
Scientific American(十)月
VOA's Weekly Science and Technology Magazine Art Chimes 05 January 2010 MUSIC: Our World theme This week on a special edition of Our World, some of our favorite stories of the past year ... including a high-tech wrinkle to that humblest of building m
VOA标准英语2010年(一月)
AGRICULTURE REPORT - Simple Ways to Protect Water Quality By Mario Ritter Broadcast: Tuesday, July 26, 2005 I'm Barbara Klein with the VOA Special English Agriculture Report. Afghans wash carrots in d
农业与发展
Cement is a major component of concrete, the world's most widely used man-made material, an integral part of roads, bridges and buildings. But making cement requires heating limestone and other materials to very high temperatures, a process that rele
VOA标准英语2010年(一月)