已知函数f（x）=x²﹣ax，g（x）=b+aln（x﹣1），存在实数a（a≥1），使y=f（x）的图象与y=g（x）的图象无公共点，则实数b的取值范围为（　　）

    One day, a teacher was giving a speech to his students. He held up a glass of water and asked the class, "How heavy do you think this glass of water is?"
    The students' answers ranged from 20 g to 500 g. "It does not matter on the weight itself. It depends on how long you hold it. If I hold it for a minute, it is OK. If I hold it for an hour, I will have an ache in my right arm. If I hold it for a day, you will have to call an ambulance (救护车). It is exactly the same weight, but the longer I hold it, the heavier it becomes. "
    If we carry our burdens (负担) all the time, sooner or later, we will not be able to carry on, the burden becoming increasingly heavier. "
"What you have to do is to put the glass down, rest for a while before holding it up again.”
    We have to put down the burden sometimes, so that we can be refreshed (使恢复) and are able to carry on.
    So before you return home from work tonight, put the burden of work down. Don't carry it back home. You can pick it up tomorrow.Whatever burdens you are having now on your shoulders, let it down for a moment if you can.

材料一  1870年前后，所有的工业都受到科学的影响。……大量生产的两种主要方法是在美国发展起来的，第一种方法是制造标准的、可互换的零件，然后以少量的手工劳动把这些零件装配成完整的单位……第二种方法出现于20世纪初，是设计出装配线……在美国，农业机械的发明也得到了促进……与这些新机械同样重要的是高粮仓、罐头食品制造厂、冷藏车、船和迅速的运输工具，它们导致一个不仅提供工业成品、也提供农业成品的世界市场。

——斯塔夫里阿诺斯《全球通史——1500年以后的世界》

材料二  资本主义国家将资本输出作为金融资本对外扩张的重要手段，从而加速了资本的跨国流动，发展起 国际资本市场和金融市场，形成世界性的金融资本体系。

——刘金源等《全球化进程中的反全球化运动》

材料三  在金字塔顶端的是少数几个欧美资本主义发达国家，其底端是处于前资本主义生产方式的广大亚非拉美落后国家。这时，世界上形成了两大类国家：一类是几个欧美资本主义工业制成品生产国，另一类是以前资本主义生产方式为主的农矿业生产国。

——千枝松《科技革命与国际分工》

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