血气分析中,以下哪一指标不是直接测得()
A.PO2
B.P50
C.PCO2
D.pH
E.以上都不正确
参考答案:B
Suffering from depression, he often his sorrows in drink.
A.swallows
B.drowns
C.sinks
D.buries
井下临时停工的地点,不得()。