单词:ethylidene perfluoride
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This is Scientific American's 60-Second Science. I'm Karen Hopkin. This will just take a minute. Beauty is only skin deep. And the beauty of shiny white teeth is even less deep. Because a new study shows that fluoride forms a thinner protective shiel
07 牙病的预防与治疗 DATE=2-27-01 TITLE=SCIENCE IN THE NEWS #2113 - (1)Dental Health BYLINE=Nancy Steinbach VOICE ONE: This is Sarah Long. VOICE TWO: And this is Bob Doughty with Science in the
AS IT IS 2014-05-25 Scientists Search for New Ways to Stop Mosquitoes 科学家们寻找新的方法来对付蚊子 The sound of a mosquito can mean trouble in many parts of the world. The bite of a mosquito can be deadly. Today, we will hear about s
It's Not Easy Being a Kid!-儿童英语故事三
美科学家研发新一代驱蚊剂 In many regions of the world, mosquitoes are a seasonal pest. In other regions, they carry serious diseases like malaria. The World Health Organization estimates that almost 630,000 people died of malaria-related
Is it necessary to have cavities in the baby teeth repaired? 乳牙蛀成了洞还有必要补上吗? If the baby teeth are going to fall out, I don't think that it matters if they become decayed. 如果乳牙是要脱落的,我想蛀了也没有关
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A cluster of villages in China's Guizhou province has been plagued by an outbreak of disease that damages teeth and bones. Now, a new study by Chinese and American researchers puts the blame on polluted coal burned in home fireplaces. In small quanti
Promising Mosquito Repellent Announced美科学家研发新一代驱蚊剂 In many regions of the world, mosquitoes are a seasonal pest. In other regions, they carry serious diseases like malaria. The World Health Organization estimates that almost 6
One Police stops on police vehicle outside one Victoria's Bar. After the preparation, as necessary arrests?, this liquor drive slightly mixes. Suddenly he sees to have a young people shakely goes out from bar, spend the many figures only then finds
Ah yes.The ol' fluoride rinse at the dentist. Not pleasant. But hey, good for your teeth, right? 没错,这是牙医洗牙用的含氟漱口水。确实够闹心的。但毕竟对你的牙齿有益不是吗? Well now materials scientists have been
77 流星雨成因探索 Date=8-2-01 Ttle=science report - the Perseid meteor shower Bline=Mario Ritter (Start at 59
SCIENCE IN THE NEWS - November 26, 2002: Dental Health By Nancy Steinbach VOICE ONE: This is Steve Ember. VOICE TWO: And this is Bob Doughty with Science in the News, a VOA Special English program abo
今天我们要学的词是 fluoride. Fluoride 氟化物。The U.S. government is lowering the recommended amount of fluoride added to drinking water for the first time in more than 50 years. 美国政府50多年来首次降低饮用水建议添加的氟
One of my fellow midshipmen at the U. S. Naval Academy was performing poorly in class and reported to his company officer for counseling., Your marks are deplorable! the officer scolded. Is there a problem-that has kept you from studies?No, sir, the
BEIJING, Aug. 8 (Xinhua) -- China on Wednesday started to review anti-dumping measures it imposed on chloroprene rubber imported from a Japanese company, the Ministry of Commerce said. The move came after the ministry received complaints that Japan E
On its website, a history of the company makes no mention of leador indeed of Thomas Midgleybut simply refers to the original product as containing a certain combination of chemicals. 在它的网站上,公司的历史没有提及铅──也没有提
By counting back through these layers and measuring the amount of lead in each, he could work out global lead concentrations at any time for hundreds, or even thousands, of years. The notion became the foundation of ice core studies, on which much mo
Lead is a neurotoxin. Get too much of it and you can irreparably damage the brain and central nervous system. Among the many symptoms associated with overexposure are blindness, insomnia, kidney failure, hearing loss, cancer, palsies, and convulsions
If you were going to a restaurant and wanted a healthier option, 如果你去饭店,你想吃得健康一点, which would you choose, grilled or fried chicken? 你会选择哪种食品呢,烤鸡还是炸鸡? Now most people would answer grill