铅蓄电池总反应为PbO2＋Pb＋2H2SO4═2PbSO4＋2H2O，下列关于铅蓄电池的说法正确的是
| A．在放电时，正极发生的反应是 Pb(s) +SO42―（aq）= PbSO4(s) +2e― |
| B．在放电时，该电池的负极材料是铅板 |
| C．在充电时，电池中硫酸的浓度不断变小 |
| D．在充电时，阳极发生的反应是 PbSO4(s)+2e―=" Pb(s)+" SO42―（aq） |
Jenny nearly missed the flight______ doing too much shopping.
| A．as a result of | B．on top of | C．in front of | D．in need of |
The CDs are on sale! Buy one and you get ______ completely free.
| A．other | B．others | C．one | D．ones ks |
I’m sure that your letter will get______ attention. They know you’re waiting for the reply. 
| A．continued | B．immediate | C．careful | D．general |
All the dishes in this menu, ______ otherwise stated, will serve two to three people. 
| A．as | B．if | C．though | D．unless |
The children loved their day trip, and they enjoyed the horse ride ______.
| A．most | B．more | C．less | D．little |