【单选题】在两级放大电路中,已知各自单级20lg|AVM1| = 40dB,fL1 = 4Hz,fH1 = 20kHz;20lg|AVM2| = 30dB,fL2 = 400Hz,fH2 = 150kHz。则两级放大电路的电压增益为 ,上限截止频率约为 ,下限截止频率约为 。
【判断题】陕西临潼华清池、重庆统景温泉属于水域风光。
【单选题】在两级放大电路中,已知各自单级20lg|AVM1| = 40dB,fL1 = 4Hz,fH1 = 20kHz;20lg|AVM2| = 30dB,fL2 = 400Hz,fH2 = 150kHz。则两级放大电路的电压增益为 ,上限截止频率约为 ,下限截止频率约为 。
【单选题】建构拉伸特征时出现失败的原因主要有( )
【单选题】According to the passage, the difference between DSL and cable modems is _____________.
A.
DSL is faster than cable modems
B.
DSL is more vulnerable to viruses
C.
you have to connect if you want to surf the Internet using DSL, while you don’t if you use cable modems.
D.
DSL is superior to cable modems
【简答题】A.cables B.hosts C.servers D.modems
【判断题】Modems can be classified external ones and internal ones.
【单选题】In which of the following exchanges is there a grammatic mistake?
A.
---Have they removed their furniture? ---They have done the desks, but that's all so far.
B.
---Does granny look after you every day? ---She can't do at weekends, because she has to go to her own house.
C.
---Can lions climb trees? ---No, but leopards can.
D.
---Did the lions seem hungry? ---No, but they did restless.