单词:cesium astrophyllite
单词:cesium astrophyllite 相关文章
[00:06.37]The United States has a new official clock. [00:10.95]The clock began operating late last year in the American city of Boulder,Colorado. [00:18.39]Experts say the new clock is so exact that it will neither gain nor lose so much as one secon
by Michael W. Flynn First, a disclaimer: Although I am an attorney, the legal information in this podcast is not intended to be a substitute for seeking personalized legal advice from an attorney licensed to practice in your jurisdiction. Further, I
by Michael W. Flynn First, a disclaimer: Although I am an attorney, the legal information in this podcast is not intended to be a substitute for seeking personalized legal advice from an attorney licensed to practice in your jurisdiction. Further, I
Neil: This is Real English from BBC Learning English. Im Neil. Helen: 嗨,大家好,我是 Helen。 Neil: Today were going to look at words and phrases that have recently become part of the English language. Helen: 在地道英语这个节目中,我们来一块儿学习
Youve given some thought to oxygen, carbon, uranium. But youve probably never mused about the element ytterbium, symbol Yb. A new study by scientists at the National Institute of Standards and Technology, or NIST, says that ytterbium could find a rol
By Cathy Majtenyi Nairobi, Kenya 06 December 2007 Kenya's capital, Nairobi, is home to one of Africa's largest dumpsites. A recent United Nations study found that nearly half of the children surveyed who live near the dumpsite suffer from serious med