After twenty-third hour at night, the house was quiet. I didn't go to bed. Under the strong light, I looked sadly before me at a huge pile of that troublesome thing they call “books”.

    I would have my important examination the next day. “When can I go to bed?” I asked myself. I didn't answer, in fact I dared not.

    As soon as the clock struck twelve, I suddenly heard and couldn't help crying “Oh, dear! Many more books to read before I can go to bed!” We students are the most wretched creatures in the world. Dad does not agree with me on this. He didn't have to work so hard when he was a boy.

    When the clock struck one, I felt I was hopeless now. I forgot all I had learned. I was too tired to go on. I did the only thing I could. I prayed, “Oh, God, please help me pass the exam tomorrow. I do promise to work hard afterwards, Amen.” My eyes were so heavy that I could hardly open them a few minutes later, with my head on the desk, I fell asleep.

已知反比例函数y=$\frac{a-2}{x}$的图象在第二、四象限，则a的取值范围是（　　）

如果卡车空载和满载时都以同样的速度行驶，那么，空载时具有的动能 ____满载时具有的动能．空载时的惯性 ____满载的惯性．（选填“大于”、“小于”或“等于”）．发电机的发明，使人类大规模用电成为可能，开辟了电气化时代．电能属于 ____次能源；如图的四幅图中能说明发电机原理的是　 ____　图．

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***对我国社会主义建设道路的成功探索是