【简答题】( )把基带信号经过载波调制后,把信号的频率范围搬移到较高的频段以便在信道中传输(即仅在一段频率范围内能够通过信道)
【简答题】apparent convince curiosity detail fundamentalpatience respond spark stir ultimateThe speaker had noticed that his topic wasn’t popular with the audience, so he quickly ended his speech.
【多选题】地陪在送走旅游团后,应做好的后续工作主要有( )等。
【多选题】地陪在送走旅游团后,应做好的后续主要有( )等。
【简答题】This became apparent when the individuals he assumed to cite spoke up and said that they had never said those things. (supposition; quotation)
【多选题】地陪在送走旅游团后,应做好的后续工作主要右( )等。
【单选题】He had _______ escaped by bribing a guard.
【单选题】下列关于调制,说法不正确的是
A.
基带调制仅对基带信号的波形进行变换,使它能够与信道特性相适应。
C.
带通调制使用载波 (carrier)进行调制,把基带信号的频率范围搬移到较高的频段,并转换为模拟信号,这样就能够更好地在模拟信道中传输(即仅在一段频率范围内能够通过信道) 。
【单选题】停电操作应在断路器断开后进行,其顺序为( )。