危重呼吸衰竭患者应采用( )营养输注含支链氨基酸丰富的复合氨基酸。
A．胃肠内 B．胃肠外C．肌内注射 D．鼻饲
参考答案：B
磨机的临界转速
Why didn't you tell me there was no meeting today? I _____ all the way here _____the heavy snow.
A．needn't have driven；through
B．can't have driven；across
C．mustn't have driven；through
D．shouldn't have driven；cross
