单词：sulphur laser
单词：sulphur laser 相关文章
By Carol Pearson Washington 30 April 2008 Ten years ago, the U.S. Food and Drug Administration approved LASIK, eye surgery with a laser that enables people to see without glasses. But about five percent of LASIK procedures fail, and those patients ca
VOA常速英语2008年（四月）
Up in the Sierra Madre Mountains, in a bowl-shaped valley, is the capital of Mexico. 在马德雷山脉上有一个碗形的山谷，里面坐落着墨西哥的首都， It is called Mexico City, so you dont have to learn a new name. 叫做墨西哥城
美国学生世界地理教材
Lesson 57 Sulphur 第57课 硫 Did you ever have to take a mixture of brimstone and treacle? This mixture has not a pleasant taste, but it is a useful medicine; and if it will do us good, we should not care much whether it has a nice taste or not. 小朋
英国学生科学读本
The fumes of burning sulphur will bleach straw, silk, and other things, and make them white and clean. These fumes are also useful for killing the germs which cause fevers and other diseases. 燃烧的硫磺冒出的烟，可以漂白稻草、丝绸和
英国学生科学读本
By Paul Sisco Washington 14 November 2007 At the McDonald Observatory in western Texas, a unique space program has been quietly underway for more than 30 years. It is called the Lunar Laser Ranging Program. VOA's Paul Sisco has more. Research scienti
VOA常速英语2007年（十一月）
Oh, my God, are you choking? Oh, my God, I feel like you're choking! Is anyone here a doctor? What am I saying? I forgot where I am. Has anyone here ever seen What do you do when a girl is choking? I just back up a few inches. What do we do? What do
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