0.004007有_____个有效数字 [ ]
A.2
B.3
C.4
D.5
答案:C
-Would you mind passing me some water?
-________I’ll do it right now. [ ]
A. I'm not sure
B.Of course not
C.Enjoy yourself
当手机开机时,手机将寻找()所允许的所有频点
A.PSTN
B.VLR
C.HLR
D.BSC
E.PLMN