_____ valuable advice you gave me! [ ]
A. What a
B. What an
C. What
D. How
答案:C
燃气的储存形式有()。
A.储气管
B.管道
C.管束
D.地下,低温液化
IPv4/IPv6双栈校园网接入设备是()
A.S2823G
B.S2828G
C.2128G
D.2121G