物质对X线的总衰减系数包括()
A.光电衰减系数
B.相干散射衰减系数
C.康普顿衰减系数
D.电子对效应衰减系数
E.以上都是
参考答案:E
下列反应,不属于氧化还原反应的是( )
A.CaCO3═CaO+CO2↑
B.2HClO═2HCl+O2↑
C.2Na2O2+2CO2═2Na2CO3+O2
D.Fe+CuSO4═FeSO4+Cu
In the city the old _____.[ ]
A. take good care of
B. are taken good care of
C. is taken good care of
D. are been taken good care of