单项选择题
A.ev=0.63;n=45.3%;Sr=94%;γd=1.47N/cm3 B.ev=0.83;n=45.3%;Sr=94%;γd=1.47N/cm3 C.ev=0.83;n=4.53%;Sr=94%;γd=l.47N/cm3 D.ev=0.83;n=45.3%;Sr=94%;γd=14.7N/cm3