单词:strontium chloride fluoride
单词:strontium chloride fluoride 相关文章
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
New Solar Cell Minimizes Environmental Risks in Manufacturing Process 新的太阳能电池减少生产中对环境的危害 Scientists in England report the development of a new solar cell that minimizes environmental risks in the manufacturing proc
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
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
DAVID GREENE, HOST: Families across the United States are fighting with the federal government over a deadly chemical. Dozens of people have died from inhaling methylene chloride. This is an ingredient in common paint removers. NPR's Rebecca Hersher
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
Every winter some twenty million tons of salt are dumped on America's road.That sodium chloride melts the ice, so it prevents its formatin, helping to prevent accidents. But road salt has its downside. This is not very economical because salt is main
This week on Why Tell Me Why, we are finding out why the oceans are so salty. So the oceans are salty because the oceans have been around, lets say, for over five hundred million years. And over the course of time what we found out is that weve alway
Soon after taking up his position, Davy began to bang out new elements one after anotherpotassium, sodium,magnesium, calcium, strontium, and aluminum or aluminium, depending on which branch of English you favor. 上任不久,戴维开始宣布发现一
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
Tony: Who did you invite over for dinner Saturday? Carmela: I invited Keith, Sung, Stephanie, and Luis. Tony: You didnt! Carmela: I did. Why? Tony: Youre going to have a hard time cooking for them. Keith is a vegan and only eats food thats organic. S
First off, I'll mention that at the bottom of the sea there exist veins of zinc, iron, silver, and gold whose mining would quite certainly be feasible. 首先,我对您说,海底有锌、铁、银、金等矿藏,开发并不是不可能的事。