呼吸性酸中毒合并代谢性碱中毒的血气改变有()
A.pH下降
B.HCO3-减少
C.血钾降低
D.血氯降低
E.二氧化碳分压下降
参考答案:C, D
风湿病常见的联合瓣膜损害是
A.二尖瓣和肺动脉瓣B.二尖瓣和三尖瓣C.二尖瓣和主动脉瓣D.主动脉瓣和肺动脉瓣
He is over fifty, but he looks as though he()only in his thirties.
A.were
B.is
C.will be
D.has been