题目

 下列与RNA有关的叙述正确的是   A. RNA彻底水解后能生成6种小分子物质   B. 合成RNA的过程有DNA聚合酶参与   C. 细胞内tRNA的种类等于组成蛋白质的氨基酸种类   D. 大肠杆菌中rRNA的合成与核仁有关 答案：AI'm sorry. I took your umbrella _______. I just realized it when I got home. [     ]A. by chance      B. on purpose     C. by mistake     D. by violence