将钠、镁、铝各0.3 mol分别放入100 mL l mol/L的盐酸中,同温同压下产生的气体体积比是[ ]
A.1:2:3
B.6:3:2
C.3:1:1
D.1:1:1
答案:C
Don't talk about such a thing in the________of young children.[ ]
A. appearance
B. surface
C. existence
D. presence
梗阻性黄疸病人下列哪项检查对诊断价值不大()。
A.低张十二指肠钡餐检查
B.B型超声
C.经皮经肝穿刺胆道造影
D.经内镜逆行胰胆管造影
E.静脉法胆道造影