题目

In order to continue to learn by ourselves after leaving school, we must  ______ learn how to study in the school now ．        A．after all         B．in all          C．above all       D．first of all 答案：C 解析: 略下列关于试剂存放的叙述正确的是（　　）A．浓硫酸的装运包装箱应贴上如图所示的标识B．金属钠保存在CCl4中（钠的密度小于CCl4）C．氢氧化钠溶液保存在带玻璃塞的玻璃瓶中D．硝酸银溶液存放在无色试剂瓶中