If he _____ here, that would be very good. [ ]
A. is
B. was
C. were
D. has been
答案:C
在滑参数停机过程中,降温,降压应交替进行,且应先()。
胎儿窘迫,血氧降低,首先出现的是下列哪种情况:
A.呼吸性酸中毒B.代谢性酸中毒C.呼吸性碱中毒D.代谢性碱中毒E.以上都不是