动脉血PaCO2的参考值范围是()
A.45~55mmHg
B.30~40mmHg
C.45~50mmHg
D.35~45mmHg
E.35~40mmHg
参考答案:D
电力部分安全生产的方针是什么?
Whenaspeetrophotometerisused,weshouldpayattentiontotheinfluenceofsolventonabsorbance.Thesolventinthereferencecellshouldbe
A.providedbythesamemanufactoryB.producedinthesamecityC.inthesamesizeD.inthesameconcentrationE.ofthesamebatch