若调制信号的最高频率为3000Hz,最低频率为300Hz,则单边带信号的带宽为()。
A、2700Hz
B、6000Hz
C、600Hz
D、540Hz
参考答案:A
—You aren't a stranger, are you?
— , don't you remember me at the school gate ten minutes ago? [ ]
A. Yes ; to see
B. No ; seeing
C. No ; saw
D. Yes ; seeing
公民下落不明满( )年的,利害关系人可以向人民法院申请宣告其死亡。
A.1B.2C.3D.4