题目

 The weather turned out to be fine yesterday. I_____ the trouble to carry my umbrella with me. A. should have taken      B. could have taken  C. needn't have taken  D. mustn't have taken 答案：C（2013?闵行区一模）将0.02mol铜片溶于100mL 9mol/L HNO3中，产生336mL气体（只含NO、NO2）．该气体与一定量O2混合后，用一定量NaOH溶液完全吸收并恰好全部生成盐，则通入的O2体积可能为（气体体积均为标准状况）（　　）A．11.2mLB．22.4mLC．56.2mLD．67.2mL