I don’t want to speak to her, but I ______.
A.do
B.have to
C.have to speak
D.must to
答案:B
计算呼吸系统的动态及静态顺应性与下列无关的参数是()
A.VT
B.Pplat
C.PEEP
D.Ppeak
E.Pmean
试分析“挤出效应”大小与IS曲线斜率的关系及其经济学含义。