氟氢化钠, 氢二氟化钠

SSS 2010-12-29

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(165) / 评论(0)

Scientific American(十二)月

太阳科普第6期

The composition of the sun lies in this bar code. 这个条码说明了太阳的组成 All the thin lines are caused by tiny amounts of complex elements 这些细细的线条，都是微量复杂元素造成的 metals like iron and magnesium. 好比说

发表于:2018-12-07 / 阅读(165) / 评论(0)

太阳科普

Dental Health

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(131) / 评论(0)

科技之光

Uses Hydrogen1 as Fuel2

Broadcast: February 14, 2003 By George Grow This is the VOA Special English Environment Report. President Bush has offered a plan to speed development of technology that uses hydrogen as fuel. His goa

发表于:2018-12-07 / 阅读(158) / 评论(0)

VOA2003（上）-科技导航

我们该选择死亡吗？

I am speaking not as a Briton, not as a European, not as a member of a western democracy, but as a human being, a member of the species Man, whose continued existence is in doubt. The world is full of conflicts: Jews and Arabs; Indians and Pakistanis

发表于:2018-12-12 / 阅读(125) / 评论(0)

英语演讲

口腔临床英语对话第29期:正畸治疗(2)

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(156) / 评论(0)

口腔临床英语对话

SSS 2008-08-01

This is Scientific Americans 60-Second Science. I am Cynthia Graber. This will just take a minute. Solar panels typically convert sunlight into electricity or heat. But photosynthetic vegetation converts sunlight into chemical energy. Now M.I.T.s Dan

发表于:2019-01-04 / 阅读(151) / 评论(0)

Scientific American(八)月

VOA标准英语2010-Pressure Mounts in US to Restrict Salt Le

Salt is believed to be the single most harmful thing in our food, contributing to high blood pressure For years doctors have been telling patients with high blood pressure to cut down on the amount of salt in their diet. Now a prestigious panel of ex

发表于:2019-01-13 / 阅读(179) / 评论(0)

VOA标准英语2010年(四)月

VOA标准英语2010年-Coal Burning Linked to Fluoride Diseas

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(139) / 评论(0)

VOA标准英语2010年(十)月

科学美国人60秒 SSS 海狸牙齿的奥秘

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(135) / 评论(0)

2018年科学美国人1月

纽约车展上电动汽车来势汹汹

NEW YORK Plug in your car, then unplug, and drive away. More and more consumers are doing just that. At the 2014 New York Auto Show many automakers unveiled electric or hybrid vehicle to address the growing global appetite for environment-friendly ca

发表于:2019-01-30 / 阅读(138) / 评论(0)

英语新闻

SCIENCE IN THE NEWS - Dental Health

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(137) / 评论(0)

科技之光

学个词 Learn a Word-VOA英语教学 2280-fluoride

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(128) / 评论(0)

英语单词荟萃

联合国考虑对朝鲜新制裁

SEOUL/WASHINGTONThe U.N. Security Council said Wednesday that it was working to craft new sanctions against North Korea after its latest nuclear test, while the United States and other world powers voiced skepticism about Pyongyang's claim that the u

发表于:2019-02-04 / 阅读(92) / 评论(0)

英语新闻

托福考试：TOEFL模拟试题

Questions 12-20 The elements other than hydrogen and helium exist In such small quantities that it is accurate to say that the universe somewhat more than 25 percent helium by weight and somewhat less than 25 percent hydrogen. Astronomers have measur

发表于:2019-02-05 / 阅读(163) / 评论(0)

托福英语

雅思单词前缀整理

PREFIX 1.a-:of;on;intensive;negative,not,without;ad-;ab-. 2.ab-:away from,off. 3. ad-:to;at;for. 4. aer(o)- :relating to air . 5.al-:all. 6.ambi-:on both sides,around. 7.amphi-:on both sides,around. 8.an-:negative,not,without. 9.ana-:upon,up,on. 10.a

发表于:2019-02-06 / 阅读(173) / 评论(0)

雅思英语

我们该选择死亡吗

December 30, 1954 I am speaking not as a Briton, not as a European, not as a member of a western democracy, but as a human being, a member of the species Man, whose continued existence is in doubt. The world is full of conflicts: Jews and Arabs; Indi

发表于:2019-02-09 / 阅读(177) / 评论(0)

英语美文

各种花样的风筝怎么说？

9月16日是墨西哥馆日，墨西哥馆五颜六色的风筝森林吸引了不少人的眼球，你知道小小的风筝里有什么大学问吗？其实风筝也有很多种分类哦，一起来看看吧。说到kite这个单词，这也许是我们

发表于:2019-02-18 / 阅读(184) / 评论(0)

英语口语

朝鲜宣布成功进行首次氢弹试验

North Korea conducted a 'successful' hydrogen bomb test, Pyongyang has confirmed. The thermonuclear weapon triggered a massive 5.1 magnitude earthquake when it exploded at 10am local time on Wednesday. 平壤方面已经证实，朝鲜成功的进行了

发表于:2019-02-18 / 阅读(110) / 评论(0)

英语新闻

万物简史第357期:孤独的行星(22)

Oxygen itself is not combustible; it merely facilitates the combus tion of other things. （氧本身是不可燃的，它只是帮助别的东西燃烧。 This is just as well, for if oxygen were corn bustible, each time you lit a match all the air

发表于:2019-02-25 / 阅读(119) / 评论(0)

万物简史

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