单词：phosphorus pentafluoride
单词：phosphorus pentafluoride 相关文章
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
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
2018年NPR美国国家公共电台2月
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
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
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
2007年VOA标准英语（七月）
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
2018年NPR美国国家公共电台7月
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
万物简史
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
英语听力文摘 English Digest