【单选题】
555定时电路端不用时，应当___。
A. 接高电平
B. 接低电平
C. 通过0.01µF的电容接地
D. 通过小于500Ω的电阻接地
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答案
A
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相关试题
【单选题】
24在8×51的程序里，若要将某个输入/输出端口设置成输入功能，应如何处理？___
A. 先输出高电平到该输入/输出端口
B. 先输出低电平到该输入/输出端口
C. 先读取该输入/输出端口的状态
D. 先保存该输入/输出端口的状态
【单选题】
29在Keil µVision3里进行调试/仿真时，在哪里操作才能触动程序中断？___
A. 在Interrupt System
B. 在Cotorl Box对话框里
C. 直接单击魔术棒按钮即可
D. 直接按0键
【单选题】
36在12MHz的8×51系统里，哪一种方式一次可定时5ms？___
A. Mode 0及Mode 1
B. Mode 1及Mode 2
C. Mode 2及Mode 3
D. Mode3及Mode 1
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24. The 2016 Olympic Games ________ in Brazil. Would you like to go there?
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25. — David, look at the man in white over there．Can you tell me _______ ?
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【单选题】
( ) 32. According to the passage, which of the following may lead to inventions?
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【单选题】
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【单选题】
( ) 34. Why did the father not ask his son not to do this and do that？
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( ) 35. What would someone learn from this passage？
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( ) 36. What may be the proper Chinese for the underlined part in the passage？
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【单选题】
) 1. —Is it far from here to the bank?
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【单选题】
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【单选题】
11. When the parents arrived at the hall, the students _______ their projects.
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