题目

规范的操作是实验成功的保证。以下几种实验操作，错误的是( ) A . 酒精灯失火用湿抹布铺盖 B . 将氯化钠倒入量筒中配制液体 C . 搜集二氧化碳 D . 称量固体 答案：BI thought I _________in my project report , but the manager said he didn't see it at all.A. hand B. am handing C. have handed D. had handed