ZK3-A170型电空转辙机的额定风压为()。
A.550MPa
B.55MPa
C.5.5MPa
D.550kpa
参考答案:D
并联网络的总阻力比并联的任一巷的通风阻力()。
A、大
B、小
C、相等
— Which would you like to visit, Shanghai Expo Garden or Beijing Bird Nest?
— . I prefer to enjoy the 2010 FI World Cup at home.
A.Both
B.Either
C.Neither
D.None