I don’t need the dictionary _____. You can use it now.A. at presentB. at that timeC. at a timeD. for one time 答案:A at present 目前,现在;at that time 在那时;at a time 曾经。 用化学分析法测得某种有机物的元素组成及其含量分别是:C:92.393%,O:3.518%,N:2.754%,H:1.214%,S:0.006%,Fe:0.006%,该物质最可能的是
A.蛋白质 B.糖类 C.脂肪 D.核酸