These figures began to appear during the 15 th century B. C. in Mycenaean sanctuaries and tombs.

这些数字开始出现在15世纪迈锡尼保护区和墓葬年代。

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It is obvious th at A. C. motors are superior to D. C. motors in many appli cations.

显然，交流电机在许多应用场合比直流电机优越。

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It is obvious th at A. C. motors are superior to D. C. motors in many appli cations.

显然，交流电机在许多应用场合比直流电机优越。

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