皮肤黏膜出现发绀时,毛细血管血液还原血红蛋白至少超过()
A.75g/L
B.50g/L
C.100g/L
D.45g/L
E.30g/L
参考答案:B
25Hz相敏轨道电路叠加UM71轨道电路长度是多少?
I am good at playing football, but Jack _____ well in _____ basketball.[ ]
A. do, play
B. does, to play
C. does, play
D. does, playing