碳的诸多同位素the many isotopes of carbon碳的化合价是4价。Carbon has a valency of 4.通过环氧化和氧化就得到外消旋的含十八个碳的昆虫返动激素.Epoxidation and oxidation gave the racemic C 18 - juvenile hormone....
The family are rich, and extremely sophisticated and cosmopolitan.这家人很富有，老于世故，而且见多识广。She 's a real cosmopolitan.她是个真正的世界主义者。Alexandria's population was cosmopolitan, but mainly Greek.亚历山大市的居民来自世界各地, 但以希腊人居多....
科恩星期天一整天都在家无所事事。On Sunday Cohen lay around the house all day.他们还留下了一张名片，上面印着肖恩·林奇的名字。They also left a card, imprinted with the name Sean Lynch.我当时不知道罗恩有那么坚强的个性。I didn't know Ron had that much strength of character....
This is a Geiger counter for detecting radioactivity.这是一种盖革计数管,用来测量辐射的.A metal called uranium gave off a kind of radiation, which Marie Curie later called radioactivity.一种叫铀的金属发出一种射线, 后来玛丽·居里把这种现象称为放射性.The site was found...
我们通常以为被拦路抢劫的受害者是老年人。We usually think of a victim of mugging as being someone elderly.我们本以为他会采取更负责的态度。We would have thought he would have a more responsible attitude.谁都会以为你和那个姑娘恋爱了。Anyone would think you were in love with...
It was performed in fashionable Casino ballrooms.人们在时髦的娱乐舞厅里跳这种舞蹈.Some settled into ballrooms or theaters or hotels for weeks or months at a time.有的乐队在舞厅、剧院或旅馆作数月甚至数月的逗留....