题目

— Can you give me the right answer? —Sorry, I ______ . Would you repeat that question? A. hadn't listened          B. haven't listened         C. don't listen               D. wasn't listening 答案：D 解析: 由关键词：repeat that question可以推出过去那时没有听。烧开水的铝壶用久了会在壶底沉积一层白色沉淀，它的成分中含有CaCO3，清洗铝壶时可用少量稀盐酸溶解除去，化学方程式是：__，但盐酸用量过多，则会损坏水壶，因为__．