以非质子酸氯化亚锡为催化剂,催化合成了丁醛-1,2-丙二醇缩醛.Butyraldehyde 1,2 proparediol acetal was synthesized by using stannous chloride as catalyst.以非质子酸氯化亚锡为催化剂,催化合成了丁醛-1,2-丙二醇缩醛.Butyraldehyde 1,2 propanediol acetal was synthesized by using st...
In late January a Brobdingnagian battle erupted over a Lilliputian water dweller.1月底,一种小小的水栖生物掀起了一场大战.Alongside it, NASA is developing the Brobdingnagian Ares V , a 380 - ft.与此同时, 美宇航局还在开发“战神5号”火箭....
Hypertension nearly triples the risk for men and doubles it for women.高血压将使男性患病风险增至普通风险水平的近三倍(女性为两倍).We shall discuss quadruples, triples, trees, and indirect triples.我们将讨论四元组, 三元组, 树和间接三元组.The method of deducing Pythago...
他们坚持要比淡而无味的英国货味道更好的巧克力。They insist on tastier chocolate than the anaemic British stuff.较大的公司能够提供一系列更好的服务。The larger firm was capable of providing a better range of services.通过采取更好的坐姿，你的腹部马上就会看起来平坦一些。You can make your sto...
The pill is the most efficient method of birth control.服用避孕药是最有效的避孕方法。The process of replication is very quick and efficient.复制的过程快捷、高效。She was efficient and reliable.她办事很有效率，也很可靠。...