【单选题】【消耗次数：1】
若使用频率为8MHz的晶振，则单片机的机器周期为 ( )。
①
0.5微秒
②
1微秒
③
1.5微秒
④
2微秒
参考答案：
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相关题目
【简答题】
用汇编写一个51单片机的101微秒延时程序，已知晶振频率=12 MHz
随机题目
【单选题】
已知一立体的主视图和俯视图，关于它的左视图，哪一种判断是正确的<img src="https://upload.icve.com.cn:89/ssykt/y@0558842F4F1489681A48F02C0BBC3B4B.png/download?time=636534318167593943&token=3C011857C82CBAC7A9D804F1ADC7BD2B&filename=%E8%87%AA%E5%8A%A8%E4%B8%8A%E4%BC%A0p5elah6ofilfkbdrcydsgg20180205125016.png"/>
①
（a）、（b）正确
②
（b）正确
③
（d）正确
④
（c）正确
【单选题】
直线AB的正面投影与OX轴倾斜，水平投影与OX轴平行，则直线AB是( )
①
Normal
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7.8 磅
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2
false
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EN-US
ZH-CN
X-NONE
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水平线
②
Normal
0
7.8 磅
0
2
false
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EN-US
ZH-CN
X-NONE
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正平线
③
Normal
0
7.8 磅
0
2
false
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EN-US
ZH-CN
X-NONE
侧垂线
④
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
/* Style Definitions */
table.MsoNormalTable
{mso-style-name:普通表格;
mso-tstyle-rowband-size:0;
mso-tstyle-colband-size:0;
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mso-hansi-font-family:等线;
mso-hansi-theme-font:minor-latin;
mso-font-kerning:1.0pt;}
一般位置线
【单选题】
A点坐标为（10、20、30），B点坐标为（30、20、30）则AB距离为______。
①
Normal
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7.8 磅
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mso-hansi-theme-font:minor-latin;
mso-font-kerning:1.0pt;}
正垂线
②
Normal
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7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
/* Style Definitions */
table.MsoNormalTable
{mso-style-name:普通表格;
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mso-para-margin-bottom:.0001pt;
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mso-bidi-font-size:11.0pt;
font-family:等线;
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mso-hansi-theme-font:minor-latin;
mso-font-kerning:1.0pt;}
侧垂线
③
Normal
0
7.8 磅
0
2
false
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EN-US
ZH-CN
X-NONE
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mso-fareast-theme-font:minor-fareast;
mso-hansi-font-family:等线;
mso-hansi-theme-font:minor-latin;
mso-font-kerning:1.0pt;}
正平线
④
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
/* Style Definitions */
table.MsoNormalTable
{mso-style-name:普通表格;
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mso-bidi-font-size:11.0pt;
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mso-fareast-theme-font:minor-fareast;
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mso-hansi-theme-font:minor-latin;
mso-font-kerning:1.0pt;}
铅垂线
【单选题】
mso-bidi-font-family:Times New Romanmso-bidi-theme-font:minor-bidi;
background:white;mso-ansi-language:EN-US;mso-fareast-language:ZH-CN;mso-bidi-language:
AR-SA">下列描述不正确的是
①
零件图中零件的细微结构可省略不画
②
装配图中某些紧固件可采用简化画法
③
装配图中相同结构可采用简化画法
④
装配图中零件的细微结构可省略不画
【单选题】
化工设备图常选用 两个基本视图， 设备常选用 两个基本视图。1. 卧式 2. 立式 3. 主、俯 4. 主、左
①
1,4,2,3
②
1,3,2,4
③
2,3,1,4
④
2,4,1,3
【判断题】
mso-bidi-font-family:Times New Romanmso-bidi-theme-font:minor-bidi;
background:white;mso-ansi-language:EN-US;mso-fareast-language:ZH-CN;mso-bidi-language:
AR-SA">化工设备上管口的径向方位，可以在俯视图（或左视图）上表达，也可以用管口方位图表达
①
正确
②
错误
【单选题】
设备平面布置图的定位尺寸主要以 为基准进行标注，其剖面图上的标高基准为 。1.设备的中心线 2.建筑定位轴线 3.地面 4.海平面
①
1,2
②
1,3
③
2,3
④
3,4