下列说法中用离子方程式表达正确的是 （ ）
| A．用含氢氧化铝的药物治疗胃酸过多症：OH-+H+=H2O |
| B．用亚硫酸钾溶液吸收硫酸工业尾气中的SO2：SO2+SO32-+H2O=2HSO3- |
| C．右图所示电池的反应： Cu2++2Ag=Cu+2Ag+ |
| D．用稀硫酸洗涤沾在试管壁上的氧化亚铜：Cu2O+2H+=2Cu2++H2O |
Edward, you play so well. But I ______ you played the piano. 
| A．didn’t know | B．hadn’t known |
C．don’t know | D．haven’t known |
She brought with her three friends, none of ______ I had ever met before. 
| A．them | B．who | C．whom | D．these |
I tried phoning her office, but I couldn’t _______. 
| A．get along | B．get on | C．get to | D．get through |
His sister left home in 1998, and _______since. 
| A．had not been heard of | B．has not been heard of |
C．had not heard of | D．has not heard of |
What do you mean, there are only ten tickets? There _____ be twelve
| A．should | B．would |
C．will | D．shall |