用酸性氢氧燃料电池电解苦卤水 (含Cl-．Br-．Na＋．Mg2＋)的装置如图所示 (a．b为石墨电极)。下列说法中，正确的是
A．电池工作时，正极反应式为：O2 +2 H2O + 4e-=4 OH-
B．电解时，a 电极周围首先放电的是Br-而不是Cl-，说明当其它条件相同时前者的还原性强于后者
C．电解时，电子流动路径是：负极→外电路→阴极→溶液→阳极→正极
D．忽略能量损耗，当电池中消耗0．02g H2 时，b 极周围会产生0．02g H2
BD
| 完形填空。 Jim is an American boy. He likes l football matches, 2 he hasn't enough money to buy tickets. He has to watch the matches 3 TV at home when he has 4 homework. He must go to school from Monday to Friday, so he missed (错过)a lot of important matches. A big football match would be held in the afternoon the next day. 5 wanted to watch it very much. But he couldn't, he would have a physics test in 6 afternoon. ''Can we have a video, mom?" Jim asked his mother 7 he went to school. "Then from our TV set you can record (录制)the match for me." "I'm 8 we can't afford one," his mother said. The next morning Jim came home with a smile, 9 a new video. "But where did you get the money, Jim?" The woman asked in surprise. ''That's 10 mom. I've sold our TV set." | ||||
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