单词：acid silica
单词：acid silica 相关文章
Acid Rain 酸雨 Damage from acid rain is widespread - not just in eastern North America, but throughout Europe, Japan, China, and Southeast Asia. Is the rain that's falling on your umbrella acidic? A listener's question -- on today's Earth and Sky. J
(科普英语)Earth and Sky
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
How does acid deposition affect human health? We eat food, drink water, and breathe air that has come in contact with acid deposition. Canadian and U.S. studies indicate that there is a link between t
知性英语
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
By Birungi Machrine Kampala 26 November 2007 Attacks using acid are becoming more frequent in Uganda. Up to 2003, there were only 145 recorded attacks, but over the last three years, there have already been 87. Survivors often suffer from severe emot
VOA常速英语2007年（十一月）
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