图2所示电路中Uab=0，电流源两端的电压US为（ ）V。[img=186x120]17da5a08ccb0463.png[/img] A: 40 B: -60 C: 60 D: -40
图2所示电路中Uab=0，电流源两端的电压US为（ ）V。[img=186x120]17da5a08ccb0463.png[/img] A: 40 B: -60 C: 60 D: -40
已知US=25V，IS=3A，R1=35Ω，R2=5Ω，R3=40Ω，用戴维宁定理求图示电路中的电压。53f372e6131b21cdfc448968a927c9d6.png92cd02ebc55ca8949822edd474685f91.png
已知US=25V，IS=3A，R1=35Ω，R2=5Ω，R3=40Ω，用戴维宁定理求图示电路中的电压。53f372e6131b21cdfc448968a927c9d6.png92cd02ebc55ca8949822edd474685f91.png
Are there enough books for ____? A: three us B: us three C: all us D: the three us
Are there enough books for ____? A: three us B: us three C: all us D: the three us
______ agrees to your plan. A: Anyone of us B: No one of us C: None of us D: Someone of us
______ agrees to your plan. A: Anyone of us B: No one of us C: None of us D: Someone of us
设从磁盘将一块数据传送到缓冲区所用时间为80us,将缓冲区中数据传送到用户区所用时间为40us,CPU处理一块数据所用时间为30us.如果有多块数据需要处理，并采用单缓冲区传送某磁盘数据，则获取并且处理中间块数据所用总时间为（）us。
设从磁盘将一块数据传送到缓冲区所用时间为80us,将缓冲区中数据传送到用户区所用时间为40us,CPU处理一块数据所用时间为30us.如果有多块数据需要处理，并采用单缓冲区传送某磁盘数据，则获取并且处理中间块数据所用总时间为（）us。
Mr. Yang ______. A: teaches math us B: teaches us to math C: teaches math to us D: us teaches math
Mr. Yang ______. A: teaches math us B: teaches us to math C: teaches math to us D: us teaches math
What does sleeping help us? A: It helps us stay healthy. B: It helps us improve our memory. C: It helps us reduce stress. D: It helps us lose weight.
What does sleeping help us? A: It helps us stay healthy. B: It helps us improve our memory. C: It helps us reduce stress. D: It helps us lose weight.
已知一脉冲信号其周期为10uS，经过一个四分频器后，输出脉冲的周期为（）。 A: 40uS B: 20uS C: 10uS D: 2.5uS
已知一脉冲信号其周期为10uS，经过一个四分频器后，输出脉冲的周期为（）。 A: 40uS B: 20uS C: 10uS D: 2.5uS
Miss Li is ______ English teacher. She likes______ very much. A: our, we B: our, us C: us, our D: us, us
Miss Li is ______ English teacher. She likes______ very much. A: our, we B: our, us C: us, our D: us, us
The new washing-machine has been______. A: giving us trouble B: getting us trouble C: asking us trouble D: looking for us trouble
The new washing-machine has been______. A: giving us trouble B: getting us trouble C: asking us trouble D: looking for us trouble