如果采用9MHz晶振，1个机器周期为（）us A: 1 B: 1.5 C: 2 D: 2.5
如果采用9MHz晶振，1个机器周期为（）us A: 1 B: 1.5 C: 2 D: 2.5
在51单片机系统中，若晶振频率6MHz，一个机器周期等于 A: 1us B: 1.5us C: 2us D: 2.5us
在51单片机系统中，若晶振频率6MHz，一个机器周期等于 A: 1us B: 1.5us C: 2us 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
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
【单选题】如图所示电路，Us=10V，R1=3欧姆，R2=2欧姆，R3=2欧姆，开关S闭合前电路处于稳态，t=0时开关S闭合。t=0+时，iL1(0+)=_________A【图片】 A. 2 B. -2 C. 2.5 D. -2.5
【单选题】如图所示电路，Us=10V，R1=3欧姆，R2=2欧姆，R3=2欧姆，开关S闭合前电路处于稳态，t=0时开关S闭合。t=0+时，iL1(0+)=_________A【图片】 A. 2 B. -2 C. 2.5 D. -2.5
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
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.
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