单词：gas ring laser
单词：gas ring 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）
EXPLORATIONS - The History of the Laser Welcome to EXPLORATIONS in VOA Special English. Im Mario Ritter. This week, we tell about one of the most recognizable objects in science fiction the laser. It is one of the best examples of how technology can
2013年VOA慢速英语(二)月
The United States Navy has demonstrated a new laser weapon operating in the Persian Gulf. The Laser Weapons System, or LaWS, is deployed on the USS Ponce transport ship. A live test firing of the weapon was recently carried out for Cable News Network
2017年VOA慢速英语(七)月
The History of the Laser Welcome to EXPLORATIONS in VOA Special English. Im Mario Ritter. This week, we tell about one of the most recognizable objects in science fiction the laser. It is one of the best examples of how technology can go from the sci
2013年VOA慢速英语(五)月
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）