钫的半衰期是22分钟.The half - life of francium is 22 minutes.钫是碱金属中密度最大的,具有放射性.Francium is the densest of the Alkali Metals and also radioactive.ㄗ欧竦托庞闷兰洞 钫叩氖谐.What will happen when monetarypolicy is tighter , with interest r...
他的辅导教师发现了他在阅读和写作方面进步的迹象。His remedial teacher sees signs of progress in his reading and writing.无迹象表明向客户售出了不适用的保险。There is no suggestion that clients have been sold inappropriate policies.昨天在华盛顿举行的中东和谈有了取得进展的迹象。Middle Eas...
I was dismayed at the news.我听到这个消息,很沮丧。The thought that she might fail the history test dismayed her.想到历史可能考不及格时, 她很沮丧。The committee was dismayed by what it had been told...委员会对所告知的一切很是惊愕。He was dismayed to find that his...
In the reaction of acetylation and nitration 1,2 ? dichloroethane was used as solvent.在乙酰化、硝化反应中引入了1,2-二氯乙烷溶剂.Polyurethane demulsifier for crude oil were prepared from polypropylene glycol, xylene, toluenediiso - cyanate...