题目

第三部分：阅读理解（共20小题；每小题2分，满分40分） 阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项 A     No one is glad to hear that his body has to be cut open by a surgeon（外科医生） and part of it taken out． Today， however， we needn't worry about feeling pain during the operation． The sick person falls into a kind of sleep， and when he awakes， the operation is finished． But these happy conditions are fairly new． It is not many years since a man who had to have operation felt all its pain． Long人类社会的发展离不开金属材料。如图是某硬铝的主要成分及相关实验。（1）将未打磨过的硬铝放入足量稀硫酸中，整个过程中的实验现象是__________（填字母）A先无气泡产生，后有大量气泡产生 B立即产生大量气泡 C无气泡产生（2）将打磨过硬铝片放入硫酸铜溶液中，写出涉及到的一个化学反应的方程式___________。（3）将一定量硝酸银溶液滴入盛放有硬铝粉末的试管中，充分反应后，过滤，得到滤渣和滤液。若滤渣中加入稀盐酸无气泡产生，则滤渣中一定含有的金属是___________。