The properties of Bell number in proper order are studied with the use of elementary method, some identities involving the sum of product of Bell number in proper order are obtained.

利用初等方法研究了有序贝尔数的性质，给出了关于有序贝尔数的一组恒等式。

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Once he was over the hump of the hill, he let the cycle glide. He slowed down on Rose Lane, found the house number, which he had memorized, and rang the bell.

一过完上坡那个最困难的路程，他就任车子自行滑动，到了罗斯小巷慢了下来，找到他记在心里的门牌号，然后按响了门铃。

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While the company's financial reports were improving, a number of vehicle recalls signalled that its famed quality was slipping, and Mr. Toyoda began to sound the warning bell.

虽然丰田公司的财报有所好转，但多起车辆召回事件表明丰田的高质量声誉正在下滑，丰田章男也开始敲响警钟。

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R.J.Bell of Pregame.com says the number of possibilities to guarantee a perfect bracket are an astronomical 9.2 quintillion.

VOA: standard.2009.03.25

Meanwhile, the manager of the Bell Rock hotel said a number of bookings have been cancelled and that was of concern as business "just ticked over" outside the tourism season.

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Maynard insisted there was no significance in the decision to drop Ian Bell down the order to number eight - he will start day three on nought not out, with partner Paul Collingwood on one.

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Mr Bell said Visit Cornwall hoped a number of campaigns which promoted the county would help to attract tourists to the region.

BBC: 'Fewer visitors' holiday in Cornwall says tourist board