单词：transparent vitreous silica
单词：transparent vitreous silica 相关文章
Plant Self-defense Plants may appear to be helpless in the face of hungry,toothy animals but many plants have evolved interesting systems of self-defense. Coarse meadow grasses are a good example. If you run your finger along a blade of coarse grass,
英语听力文摘 English Digest
AS IT IS 2015-07-14 Silica Sand Mining Worries Communities 美国硅砂矿引发社区担忧 The United States is increasing production of oil and natural gas through a process known as fracking. This process is sometimes called hydraulic fracking be
2015年VOA慢速英语(七)月
AILSA CHANG, HOST: Despite mounting evidence and a stream of dire warnings, federal regulators and mining companies failed to protect coal miners from toxic dust. MARY LOUISE KELLY, HOST: NPR and the PBS series Frontline spent more than a year lookin
2018年NPR美国国家公共电台12月
By David Gollust Washington 18 September 2007 The U.S. State Department is promising an open and transparent investigation of a Baghdad shooting incident Sunday involving an American security contractor that left 11 people dead. The Iraq interior min
2007年VOA标准英语（九月）
KHARTOUM, Jan. 17 (Xinhua) -- The Arab League (AL)（阿拉伯联盟） Mission for monitoring south Sudan referendum（公民投票权） on Monday said that the polling process was characterized by high transparency and integrity with international
英语新闻
BEIJING, June 1 (Xinhua) -- A system is to be launched in China to make deals concerning government-financed infrastructure construction projects in water conservancy, transport and railways more transparent. Sources with a special anti-corruption ag
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