单词：thin-layer chromatograph
单词：thin-layer chromatograph 相关文章
CHAPTER ONE [00:44.25]READING [00:45.74]Page 2 and 3 [00:48.43]THE YOUNG GREEN CONSUMER GUIDE [00:51.51]Review by Tony Ma [00:54.62]This book says that our world is in danger [00:59.32]It is vital that we do something to save the earth [01:04.21]Firs
上海牛津初中英语九年级
I first heard about the ozone layer about twenty years ago. I was still in school. I thought it was interesting, but I didnt take it seriously. It was a bit like science fiction, I mean, how could there be a giant hole in the atmosphere? Over the yea
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There is a special day to recognize the importance of the ozone layer. In 1995, the United Nations General Assembly decided September 16th is the International Day for the Preservation of the Ozone Layer. This is the date on which countries signed th
英语课程学习计划和讲义
This is Scientific Americans 60-Second Science. Im Sophie Bushwick. Got a Minute? What's the best way to find out if an unknown mixture contains a specific substance, like an environmental contaminant? You could use an expensive, bulky gas chromatogr
Scientific American(八)月
A: May I exchange this DVD player? B: Certainly. Do you have your receipt? A: Here you are. B: Now, why do you want to exchange it? A: It won't play a DVD. B: I'm sorry. I'll get you a new player. A: At first, I thought it was me. B: Okay, here's a n
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I first heard about the ozone layer about twenty years ago. I was still in school. I thought it was interesting, but I didnt take it seriously. It was a bit like science fiction, I mean, how could there be a giant hole in the atmosphere? Over the yea
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