输尿管结石病人手术前必须进行()。
A.多饮水
B.多活动
C.拍腹平片进行结石定位
D.输液
E.尿常规检查
参考答案:C
Studies show that people are more to suffer from back problems if they always sit before computer screens for long hours.
A.likely
B.possible
C.probable
D.sure
洗衣机工作时,通过它的电流是0.8A,那么1min内通过洗衣机的电荷量是______C,接在220V电路上连续使用两小时消耗电能______kW•h.