对工艺管线进行空气吹扫时,要保证气体的流速()。
A、≥1m/s
B、≥5m/s
C、≥20m/s
D、≥40m/s
参考答案:C
休克时主要的代谢改变是()。
A.酸中毒、高血钾
B.碱中毒、低血钾
C.低镁血症、低渗性脱水
D.低血钙、低血糖
E.成人呼吸窘迫综合征
When people want to relax themselves, they prefer_______ TV or listen to music rather than ______
newapapers. [ ]
A. Watching; read
B. watching; to read
C. to watch; read
D. to watch; reading