[化] 三氟氧化磷; 磷酰氟

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

发表于:2018-12-02 / 阅读(179) / 评论(0) 分类 Scientific American(十二)月

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

发表于:2018-12-07 / 阅读(138) / 评论(0) 分类 科技之光

The little splints of wood which we call matches are made out of deal or pine wood which has been soaked in melted paraffin wax to make it burn more easily. 这种被我们称之为火柴的薄木片由欧洲赤松(松树)制成, 在液体的石蜡

发表于:2018-12-18 / 阅读(131) / 评论(0) 分类 英国学生科学读本

Have you ever had a problem getting a match to light? If so, you might be using the wrong type of match. There are actually two different types of matches: safety matches and strike-anywhere matches. 以前你点燃火柴时有没有点不着的时候呢

发表于:2018-12-18 / 阅读(119) / 评论(0) 分类 2018年NPR美国国家公共电台2月

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

发表于:2018-12-27 / 阅读(167) / 评论(0) 分类 口腔临床英语对话

86 去痛片须慎用 DATE=8-16-01 TITLE=SCIENCE REPORT - OxyContin Warning BYLINE=Jerilyn Watson (Start at 1'02

发表于:2019-01-02 / 阅读(171) / 评论(0) 分类 科技之光

This is Scientific American's 60-Second Science, I'm Christopher Intagliata. Got a minute? Life on earth requires six basic ingredientscarbon, hydrogen, nitrogen, oxygen, sulfur and phosphorus. Those six elements are the building blocks for DNA and R

发表于:2019-01-08 / 阅读(147) / 评论(0) 分类 Scientific American(十二)月

This is the VOA Special English Agriculture Report. Hogs at an Ohio farm Research shows that waste from pigs that are fed a special kind of corn may help a farmer's crops. And it also may help the environment. Any farmer who raises swine knows that

发表于:2019-01-11 / 阅读(181) / 评论(0) 分类 VOA慢速英语2008年(八)月

By Peter Fedynsky Moscow 18 July 2007 Officials in Ukraine are assessing the damage of a train crash in western Ukraine that sent huge clouds of burning phosphorus billowing into the air. The accident, which took place Monday, is raising health conce

发表于:2019-01-12 / 阅读(149) / 评论(0) 分类 2007年VOA标准英语(七月)

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

发表于:2019-01-14 / 阅读(153) / 评论(0) 分类 VOA标准英语2010年(十)月

MARY LOUISE KELLY, HOST: Summertime brings algae blooms to many parts of the country - those mats of bright green organisms that can blanket waterways. In places like Florida's Lake Okeechobee, the blooms hurt tourism. They kill fish. They threaten w

发表于:2019-01-17 / 阅读(149) / 评论(0) 分类 2018年NPR美国国家公共电台7月

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

发表于:2019-01-20 / 阅读(144) / 评论(0) 分类 2018年科学美国人1月

Beginners. Well, it's time for a new dog. For the past year, we have been a one dog family. But, you know, our dog, Rosie, is a wildly social lady. She goes crazy any time she meets another dog, a cat, a mouse, or a bird, let alone a human. But, the

发表于:2019-01-28 / 阅读(146) / 评论(0) 分类 英语博客 A cup of English

The commercial potential for the stuffwhich soon became known as phosphorus, from Greek and Latin roots meaning light bearingwas not lost on eager businesspeople, but the difficulties of manufacture made it too costly to exploit. An ounce of phosphor

发表于:2019-01-29 / 阅读(133) / 评论(0) 分类 万物简史

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

发表于:2019-01-30 / 阅读(143) / 评论(0) 分类 科技之光

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

发表于:2019-02-02 / 阅读(141) / 评论(0) 分类 英语单词荟萃

By Melinda Smith Washington 14 May 2007 Top executives of the company that makes a powerful painkiller called Oxycontin admitted this week they lied about the drug's addictive qualities in order to boost sales. As VOA's Melinda Smith reports, worldwi

发表于:2019-02-03 / 阅读(191) / 评论(0) 分类 2007年VOA标准英语(五月)

Beginners. Today, Foxy had an appointment with the vet for vaccinations and a general check-up. She is about eight months old, so she needed her second set of vaccinations. The vet also needed to see if her growth was normal and healthy. I put her in

发表于:2019-02-07 / 阅读(169) / 评论(0) 分类 英语博客 A cup of English

Matches Striking matches, on this Moment of Science. Have you ever had a problem getting a match to light? If so, you might be using the wrong type of match. There are actually two different types of matches: safety matches and strike-anywhere matche

发表于:2019-02-26 / 阅读(135) / 评论(0) 分类 英语听力文摘 English Digest
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