题干

氧气是生活中不可缺的物质,关于氧气的说法中错误的是  (   )

A:工业上可以利用分离液态空气法制氧气

B:氧气可以支持燃烧,说明氧气具有可燃性

C:氧气供给呼吸,它和体内物质反应,释放能量,维持生命活动

D:夏天鱼池内开启增氧泵,是因为温度升高,氧气在水中溶解量减少

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答案(点此获取答案解析)

B

同类题2

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。

    It was a bad time for me. I was low emotionally and tired physically. Probably because of this I hadn't shaved for a few days. Also, because I had been doing some repairs at my daughter's house, I was dressed quite scruffily(不整洁地). Boarding the bus to go home I saw it was almost full so I found a rail(扶手) to lean against.

    That's when a young woman, sitting with her child, stood up and offered me her seat. ‘Wow!' I thought. Out loud I said, “Do I look that old and tired?” She replied, “You look like you've had a tough day.” I thanked her sincerely and stayed standing.

    A moment later a man rose from his seat at the back of the bus and made his way towards me, walking past several people on the way. Then he told me about his addiction(毒瘾) problems, asked my advice, and just chatted about life for a few minutes. Then he went back to his seat. Very random!

    Watching him go, I also looked at the bus-load of people between me and his seat. He hadn't chosen to talk to those strangers. He chose to talk to this stranger, for whatever it meant to him and whatever comfort it brought him. Why?

    That's when it occurred to me. I must have looked like I had been where he was. I probably looked like a man who would understand a difficult life. I was humbled(谦卑的) and encouraged at the same time by the realization that even when we are at our lowest we can still help others — if we look like we might be able to meet them where they live or walk a while in their world.