【单选题】
设函数<img src=https://huaweicloudobs.ahjxjy.cn/E7BDD0E188CC732949B0AF368781D666.png title=XLHN$Y8]GN@OTAX(25WI[1L.png alt=XLHN$Y8]GN@OTAX(25WI[1L.png/>，则<img src=https://huaweicloudobs.ahjxjy.cn/0D916379856D4615C7EEBB5D8A1D558B.png title=P%GGVETN1[L~88J626PFI$M.png alt=P%GGVETN1[L~88J626PFI$M.png/>处（ ）
①
可导
②
连续但不可导
③
左可导但右不可导
④
右可导但左不可导
【单选题】
在截面条件相同的情况下，长柱与细长柱的极限承载力总是比短柱的低，这是由于( )。
①
长柱与细长柱的均较细长，容易产生失稳
②
长柱与细长柱的侧向挠度较大，二阶弯矩影响较大的结果
③
长柱是由于二阶弯矩影响较大的结果，细长柱是最后失稳影响的结果
④
长柱是由于失稳影响的结果，细长柱是由于二阶弯矩影响的结果
【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
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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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A、B、C三点
②
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
/* Style Definitions */
table.MsoNormalTable
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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;
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;
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mso-hansi-theme-font:minor-latin;
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B点
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;
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;
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mso-hansi-theme-font:minor-latin;
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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;
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;}
C点