Lucy didn't feel well last week. She ____ all day and all night.
在Rt△ABC中,∠C=90°,点G是重心,如果sinA=13,BC=2,那么GC的长等于 ____
把一个灯泡接到某电压不变的电源两端,灯泡的功率为100W.将一个电阻R与这只灯泡串联后接到同一电源两端,灯泡的功率为64W,设灯丝电阻不变.则电阻R消耗的功率是( )