根据图示回答，经数小时后，U形管A、B两处的液面会出现下列哪种情况(实验装置足以维持实验期间小白鼠的生命活动，瓶口密封，忽略水蒸气和温度变化对实验结果的影响)
A、A处上升，B处下降 B、A、B两处都下降
C、A处下降，B处上升 D、A、B两处都不变
答案：C
小白鼠需要呼入氧气，呼出CO2，而CO2可以溶于氢氧化钠溶液中，所以瓶内压强会降低，因此A处液面下降，B处升高，答案选C。
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| More and more people are becoming interested in the internet. They have formed a bad habit. In fact, the bad habit has become a 1 -Internet Addiction Disorder (IAD网络综合症). Staying 2 for more than six hours a day 3 working or studying, and feeling very upset from not being able to get online, are the two major symptoms (症状) of IAD. Internet addiction (上瘾) is 4 in China now. A recent research 5 that 42% of Chinese young people get quite interested in the web, while only 18% of Americans feel in the same 6 . What causes IAD? Some people believe that It's the lack (缺乏) of family care. Most children in China are the 7 ones in their families. They are only told to 8 hard, but few really care about their personal interest. So some children would like to keep 9 away from the real world. How can people stay away from IAD? Don t get online any more, go back to the real world and if it doesn't work, go to see the 10 . | |||
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