诊断呼吸衰竭最主要的依据是()。
A.动脉血气分析
B.静脉血气分析
C.胸部X线片
D.胸部听诊
E.胸部叩诊
参考答案:A
下列计算正确的是
A.3x2·4x2=12x2
B.x3·x5=x15
C.x4÷x=x3
D.(x5)2=x7
How long have they _____?[ ]
A. married
B. been married
C. be married
D. marry