-_____ was your trip?
-It was very nice.[ ]
A. What
B. Where
C. How
D. When
答案:C
以下所列病因可引起中枢性呼吸衰竭的是()
A.心力衰竭
B.氮质血症
C.病毒性脑炎
D.急性喉炎
E.支气管哮喘
塑料外壳或自动空气开关运行时保护跳闸,若需要重新恢复送电,其操作步骤是先()后合。