某500kV变电站处于Ⅲ级污秽区（2.5cm/kV），请对变电站内电气设备的绝缘水平进行选择和计算。若500kV电流互感器直径为520mm，计算互感器的电瓷外绝缘爬电距离不应小于下列何值（）？

患者，女，66岁，无牙颌，上下牙槽嵴吸收严重，伴严重下颌前突，下颌弓明显大于上颌弓。排列前牙时，下列错误的是（...

单项选择题患者，女，66岁，无牙颌，上下牙槽嵴吸收严重，伴严重下颌前突，下颌弓明显大于上颌弓。排列前牙时，下列错误的是（）

Jenny, you often get ill, so you should _______ your he...

单项选择题Jenny, you often get ill, so you should _______ your helth.look forB．look upC．looktD．cre forJenny, you often get ill, so you should _______ your helth.look for B．look up C．lookt D．cre for

You should the new words tht you don’t know how to spel...

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