音标：[,tetrә'beisik] ；

a. [化]四代的, 四元的, 四碱的

a. Capable of neutralizing four molecules of a monacid
base; having four hydrogen atoms capable of replacement by bases;
quadribasic; -- said of certain acids; thus, normal silicic acid,
Si(OH)4, is a tetrabasic acid.

《英语流行话题阅读:语境识词4500》05 Two Basic Ways to See Growth

Unit 5 Two Basic Ways to See Growth There are two basic ways to see growth: one as a product, the other as a process. People have generally viewed personal growth as an external result or product that can be identified and measured. The worker who ge

发表于:2018-12-04 / 阅读(403) / 评论(0)

英语流行话题阅读：语境识词4500

电脑英语计算机病毒

[00:00.00]Chapter 7 [00:00.91]第七章 [00:01.83]Computer Virus [00:03.17]计算机病毒 [00:04.52]Dialogue 1 [00:05.56]句型1 [00:06.61]A: Do you have virus protection software on your PC? [00:09.51]你的电脑有防毒软件吗？ [00:12.41]B:N

发表于:2018-12-05 / 阅读(481) / 评论(0)

电脑英语

破冰英语 Basic_Lesson04

Sorry,there is not text temporarily, Please help tingroom to look for it! 如果您能找到更好的听力原文，请发贴到听力原文收集区，您将会获得10到30积分的奖励! Thank you！

发表于:2018-12-07 / 阅读(420) / 评论(0)

元元的播客

破冰英语 Basic_Lesson03

发表于:2018-12-07 / 阅读(388) / 评论(0)

元元的播客

破冰英语 Basic_Lesson08

发表于:2018-12-07 / 阅读(539) / 评论(0)

元元的播客

破冰英语 Basic_Lesson01

发表于:2018-12-07 / 阅读(431) / 评论(0)

元元的播客

破冰英语 Basic_Lesson15

发表于:2018-12-07 / 阅读(429) / 评论(0)

元元的播客

破冰英语 Basic_Lesson14

发表于:2018-12-07 / 阅读(395) / 评论(0)

元元的播客

破冰英语 Basic_Lesson13

发表于:2018-12-07 / 阅读(389) / 评论(0)

元元的播客

破冰英语 Basic_Lesson12

发表于:2018-12-07 / 阅读(392) / 评论(0)

元元的播客

破冰英语 Basic_Lesson11

发表于:2018-12-07 / 阅读(398) / 评论(0)

元元的播客

破冰英语 Basic_Lesson10

发表于:2018-12-07 / 阅读(432) / 评论(0)

元元的播客

破冰英语 Basic_Lesson09

发表于:2018-12-07 / 阅读(383) / 评论(0)

元元的播客

SSS 2012-01-24

This is Scientific American Sixty Seconds Science, I'm Sophie Bushwick, got a minute? When Mexican tetra fish moved into darker caves long ago, they evolved to deal with the dark by becoming albino and going blind. A new research shows that the chang

发表于:2018-12-24 / 阅读(479) / 评论(0)

Scientific American(一)月

专业术语—中草药成分英汉对照词汇T1

T Tanshinone IIA 丹参酮IIA Tanshinone I 丹参酮I Tanshinone IIB 丹参酮IIB Taraxasterol 蒲公英甾醇 Taraxerol 蒲公英赛醇 Tauro ursodesoxy cholic acid 牛磺熊去氧胆酸 Taxifolin 花旗

发表于:2019-01-03 / 阅读(472) / 评论(0)

医务英语

美国国家公共电台 NPR New 'Basic Economy' Airfares May Not Be As Cheap As You Think

DAVID GREENE, HOST: The big three airlines - American, Delta and United - are taking on discount carriers like Spirit and Frontier by offering no-frills discounted fares called basic economy. Some are calling it misery class because among other thing

发表于:2019-01-16 / 阅读(411) / 评论(0)

2017年NPR美国国家公共电台3月

2014年ESL之日常生活 16 Basic Military Commands

Basic Military Commands Marta: Whats going on out here? Whats all that noise? Bruno: Im putting the troops through their drills. Marta: Troops?! Bruno: Watch this. Hey, I didnt tell you you could be at ease. Attention! Fall in. Forward, march! Marta:

发表于:2019-01-23 / 阅读(478) / 评论(0)

2014年ESL之日常生活

BASIC语言改变世界五十周年

May 1 marks the 50th anniversary of a special computer language aimed at enabling college students not trained in mathematics to use computers. The birth of BASIC is now seen as a major step toward the era of personal computers. 50 years ago, compute

发表于:2019-02-05 / 阅读(515) / 评论(0)

英语新闻

VOA标准英语2008年-Report Says Basic Medical Care Could Save Lives

By Douglas Bakshian Manila 06 May 2008 A new report says the lives of millions of young children could be saved each year if basic medical care and medicine are made available to the poor. Douglas Bakshian has more from Manila. The report by the U.S.

发表于:2019-02-05 / 阅读(514) / 评论(0)

VOA标准英语2008年（五月）

万物简史第212期:把铅撵出去(1)

10 Getting The Lead Out 第十章把铅撵出去 In the late 1940s, a graduate student at the University of Chicago named Clair Patterson (who was, first name notwithstanding, an Iowa farm boy by origin) was using a new method of lead isotope measur

发表于:2019-02-17 / 阅读(493) / 评论(0)

万物简史

最新学习文章

热门学习文章

热门标签

英语听力 VOA标准英语 VOA 英语歌曲口语听力提高听力材料听力教程英语学习 NPR 英语口语 VOA慢速英语美国国家电台儿童英语 VOA英语小学英语 cnn VOA常速英语标准英语英文歌曲听电影学英语英语单词英文电影慢速英语 CRI 美联社新闻美国有线新闻加州分级澳洲新闻流行歌曲常速英语 ABC新闻快递疯狂英语英语读物听力棚车少年经济学人英语词汇商务英语 VOA双语新闻 BBC 中国电台大学英语 Treasures 加州语文 BBC英语英语听力网站 VOA英语教学词汇万花筒 SSS VOA英语听力 AP 新概念分级英语英语广播听力精选英语播客英文绘本 TED演讲赖世雄英语MP3 CCTV9英语新闻 lesson 英语新闻初中英语学英语英语语法历史上的今天英文广播剧英语游戏原版英语小说英语有声读物书虫英语牛津英语读物访谈录新闻一分钟考研英语英语每日在线听新闻 Us 新概念英语地道英语单词第二册自然百科高中英语 sports 实用英语 MP3听力辛沛沛 ESL英语第一册英语每日一句 unit 新东方 GRE 每日一词 BBC听力

学英语单词

automatic spectrometer