Uracil -- a pyrimidine found in RNA that base - pares with adenine.尿嘧啶 -- 核糖核酸中的一种嘧啶,与腺嘌呤形成碱基对.The missile control system composed of two pares, the controller and the controlled object.粗略地看,导弹控制系统都是由控制器和被控对象两大部分组成的....
他写了一篇关于克里斯托弗·马洛的推测性传记。He has written a speculative biography of Christopher Marlowe.我厌烦了所有的推测。I am tired of all the speculation.眼下这只不过是个推测而已。At the moment it is only a theory....