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
Levee 堤 A levee is a system to control water levels. 堤是一种控制水位的系统。 When it rains a lot, floods can happen. 降雨很多时，就可能会发生洪水。 People build walls along rivers or coasts to prevent floods. 人们在河边
与美国小学生一起学英文第7册
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)