【单选题】【消耗次数：1】
峰值附着系数对应的滑动率一般出现在（）。
①
10％～15％
②
15％～20％
③
20％～30％
④
30％～50％
参考答案：
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相关题目
【单选题】
已知四点A（10、20、30）、B（30、20、10）、C（10、20、10）、D（20、20、30），则对H面的重影点为______。
①
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
A与D，D点可见
②
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
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B与C，B点可见
③
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
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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-ascii-theme-font:minor-latin;
mso-fareast-font-family:等线;
mso-fareast-theme-font:minor-fareast;
mso-hansi-font-family:等线;
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A与C，A点可见
④
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
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mso-hansi-theme-font:minor-latin;
mso-font-kerning:1.0pt;}
A与C，C点可见
【单选题】
已知三点A（10、20、15）、B（10、0、30）、C（0、10、0），则在坐标面上的点为______。
①
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-style-parent:"";
mso-padding-alt:0cm 5.4pt 0cm 5.4pt;
mso-para-margin:0cm;
mso-para-margin-bottom:.0001pt;
mso-pagination:widow-orphan;
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mso-bidi-font-size:11.0pt;
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mso-fareast-font-family:等线;
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A、B、C三点
②
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
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mso-style-parent:"";
mso-padding-alt:0cm 5.4pt 0cm 5.4pt;
mso-para-margin:0cm;
mso-para-margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:10.5pt;
mso-bidi-font-size:11.0pt;
font-family:等线;
mso-ascii-font-family:等线;
mso-ascii-theme-font:minor-latin;
mso-fareast-font-family:等线;
mso-fareast-theme-font:minor-fareast;
mso-hansi-font-family:等线;
mso-hansi-theme-font:minor-latin;
mso-font-kerning:1.0pt;}
B点
③
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
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B、C两点
④
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
/* Style Definitions */
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{mso-style-name:普通表格;
mso-tstyle-rowband-size:0;
mso-tstyle-colband-size:0;
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mso-style-parent:"";
mso-padding-alt:0cm 5.4pt 0cm 5.4pt;
mso-para-margin:0cm;
mso-para-margin-bottom:.0001pt;
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mso-bidi-font-size:11.0pt;
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mso-ascii-font-family:等线;
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C点
【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
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;
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mso-hansi-theme-font:minor-latin;
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正垂线
②
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
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mso-fareast-font-family:等线;
mso-fareast-theme-font:minor-fareast;
mso-hansi-font-family:等线;
mso-hansi-theme-font:minor-latin;
mso-font-kerning:1.0pt;}
侧垂线
③
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-style-priority:99;
mso-style-parent:"";
mso-padding-alt:0cm 5.4pt 0cm 5.4pt;
mso-para-margin:0cm;
mso-para-margin-bottom:.0001pt;
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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
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mso-tstyle-colband-size:0;
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mso-style-parent:"";
mso-padding-alt:0cm 5.4pt 0cm 5.4pt;
mso-para-margin:0cm;
mso-para-margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:10.5pt;
mso-bidi-font-size:11.0pt;
font-family:等线;
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mso-ascii-theme-font:minor-latin;
mso-fareast-font-family:等线;
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mso-hansi-theme-font:minor-latin;
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铅垂线
【单选题】
设一个关系模式为R(A,B,C),对应的关系内容为R={{1,10,50},{2,10,60},{3,20,72}{4,30,60}},则δB>15(R)的运算结果中具有的元组个数为（ ）。
①
1
②
2
③
3
④
4
【单选题】
设一个关系模式为R(A,B,C)，对应的关系内容为R={{1,10,50}, {2,10,60}, {3,20,72}, {4,30,60}}，则δB15(R)的运算结果中具有的元组个数为（ ）。
①
1
②
2
③
3
④
4
随机题目
【单选题】
下列四种说法中，错误的是（）
①
箭线式网络图有时需要引入虚工序
②
虚工序的作业时间等于零
③
当二个活动既具有同一个始点又具有同一个终点时，就要引入一个虚工序
④
箭线式网络图中，虚工序消耗资源，但不占用时间
【单选题】
关于动态规划的如下说法中错误的是（）
①
状态转移方程表明了各阶段之间状态的联系
②
过程指标函数必须由阶段指标函数相加得到
③
动态规划基本方程必须有边界条件
④
动态规划中决策变量可以为连续变量也可以为离散变量