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问题 问答题

下列有关电池的叙述正确的是（　　）

A．氢氧燃料电池是将热能转变为电能的装置

B．氢氧燃料电池工作时氢气在正极被氧化

C．原电池反应均是氧化还原反应

D．铅蓄电池在放电过程中，负极质量减小，正极质量增加

答案

A、氢氧原料电池也是原电池，所以氢氧燃料电池是将化学能转变为电能的装置，故A错误；

B、氢氧原料电池工作时氢气在负极上失电子被氧化，故B错误；

C、构成原电池的条件之一是：能自发的进行氧化还原反应，所以原电池反应均是氧化还原反应，故C正确；

D、根据铅蓄电池放电时，负极电极反应式为：Pb+SO42--2e-=PbSO4 ；正极电极反应式为：PbO2+2e-+SO42-+4H+=PbSO4+2H2O，所以正负极质量都减少，故D错误．

故选C．

“麻雀叫，麻雀叫，日本人，真凶暴。夺我东三省，杀我们同胞。小朋友!大家起来闹，日本糖果我不吃，东洋玩具我不要。”达首童瑶出现在下列哪一历史事件后

A．九一八事变

B．一二八事变

C．七七事变

D．八一三事变
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单项选择题

After winning a big game, athletes are often asked how they feel. Usually athletes say how (1) it is to win this big game. On the contrary, the fact is that losing a big game, or in my case, all the games, can be even harder.
From the spectators’ point of view, last year’s basketball (2) for my high school team was nothing (3) of an embarrassment. And (4) 0 and 20 is certainly nothing to be proud of, that season had a bigger impact on me than any other. As a team captain, I knew it probably wouldn’t be the (5) year, but did I ever think we would lose every game Of course not. Since six of our top players had graduated, it was clear that we were a (n) (6) team who would struggle. The struggle began earlier than expected, (7) , as our team center was suspended (禁赛) for the season, and two key members decided to (8) for some reason. At this point, dropping out probably passed through every player’s mind, but in the end, we all stuck if out, (9) to work still harder.
Then there came a time when even our (10) and given up on us. Personally, I felt like it was (11) worthwhile giving my all. I thought, if even the coach doesn’t believe in us, why should I But just as my hope began to (12) , a teammate called a meeting. He said," Nobody thinks we are going to win, but, as teammates and friends, we (13) it to each other to go all out every game. "
It was that moment that (14) me how to be a leader. It hit me that I certainly didn’t (15) the role. As a leader you can never quit (16) the team who looks up to you. It is one (17) to be named captain, feel great and go through the motions, but it is quite another to be a real captain and make sure everyone realizes their full (18) all the time.
I am sure it is great to go through without losing and bringing home awards. But in all honesty, I (19) the fact that my team lost every game last year. It may not help me to become a better basketball player, but it already has made me a better leader, and (20)

A．meanwhile
B．though
C．instead
D．somehow
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