【单选题】【消耗次数：1】
常温下乙醚的状态为：（ ）。
①
气态
②
液态
③
固态
④
以上皆有可能
参考答案：
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相关题目
【简答题】
石油沥青按常温下的状态可以分为[填空(1)]、[填空(2)]
随机题目
【单选题】
已知随机变量<imgwidth="77"height="21"v:shapes="_x0000_i1134"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image174.png">，则随机变量<imgwidth="73"height="17"v:shapes="_x0000_i1135"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image176.png">的概率密度<imgwidth="54"height="25"v:shapes="_x0000_i1136"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image178.png">（）
①
<imgwidth="131"height="49"v:shapes="_x0000_i1137"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image180.png">
②
<imgwidth="123"height="49"v:shapes="_x0000_i1138"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image182.png">
③
<imgwidth="88"height="49"v:shapes="_x0000_i1139"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image184.png">
④
<imgwidth="123"height="49"v:shapes="_x0000_i1140"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image186.png">
【单选题】
设有<imgwidth="22"height="22"v:shapes="_x0000_i1198"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds03.files/image242.png">中两组基<imgwidth="70"height="26"v:shapes="_x0000_i1199"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds03.files/image226.png">和<imgwidth="70"height="26"v:shapes="_x0000_i1200"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds03.files/image244.png">，已知<imgwidth="206"height="28"v:shapes="_x0000_i1201"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds03.files/image246.png"><imgwidth="70"height="28"v:shapes="_x0000_i1202"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds03.files/image248.png">；<imgwidth="270"height="28"v:shapes="_x0000_i1203"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds03.files/image250.png">，则从基<imgwidth="70"height="26"v:shapes="_x0000_i1204"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds03.files/image226.png">到基<imgwidth="70"height="26"v:shapes="_x0000_i1205"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds03.files/image244.png">的过渡矩阵为（）
①
<imgwidth="102"height="84"v:shapes="_x0000_i1206"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds03.files/image252.png">
②
<imgwidth="102"height="84"v:shapes="_x0000_i1207"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds03.files/image254.png">
③
<imgwidth="112"height="84"v:shapes="_x0000_i1208"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds03.files/image256.png">
④
<imgwidth="110"height="84"v:shapes="_x0000_i1209"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds03.files/image258.png">
【单选题】
设总体<imgwidth="14"height="14"v:shapes="_x0000_i1114"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image154.png">的分布函数为<imgwidth="32"height="20"v:shapes="_x0000_i1115"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image156.png">,则总体均值<imgwidth="12"height="18"v:shapes="_x0000_i1116"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image158.png">和方差<imgwidth="18"height="20"v:shapes="_x0000_i1117"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image160.png">的矩估计分别为（）
①
<imgwidth="135"height="42"v:shapes="_x0000_i1118"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image162.png">
②
<imgwidth="173"height="40"v:shapes="_x0000_i1119"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image164.png">
③
<imgwidth="186"height="42"v:shapes="_x0000_i1120"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image166.png">
④
<imgwidth="156"height="40"v:shapes="_x0000_i1121"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image168.png">
【单选题】
<imgwidth="480"height="66"v:shapes="图片_x0020_110"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds02.files/image117.png">
①
<imgwidth="62"height="26"v:shapes="图片_x0020_111"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds02.files/image118.png">
②
<imgwidth="65"height="27"v:shapes="图片_x0020_112"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds02.files/image119.png">
③
<imgwidth="57"height="27"v:shapes="图片_x0020_113"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds02.files/image120.png">
④
<imgwidth="63"height="24"v:shapes="图片_x0020_114"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds02.files/image121.png">
【单选题】
实二次型<imgwidth="170"height="28"v:shapes="_x0000_i1222"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image226.png">为正定的充要条件是（）
①
<imgwidth="18"height="24"v:shapes="_x0000_i1223"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image228.png">的秩为<imgwidth="14"height="16"v:shapes="_x0000_i1224"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image188.png">
②
<imgwidth="18"height="24"v:shapes="_x0000_i1225"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image228.png">的正惯性指数为<imgwidth="14"height="16"v:shapes="_x0000_i1226"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image188.png">
③
<imgwidth="18"height="24"v:shapes="_x0000_i1227"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image228.png">的正惯性指数等于<imgwidth="18"height="24"v:shapes="_x0000_i1228"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image228.png">的秩
④
<imgwidth="18"height="24"v:shapes="_x0000_i1229"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image228.png">的负惯性指数为<imgwidth="14"height="16"v:shapes="_x0000_i1230"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image188.png">
【单选题】
设<imgwidth="54"height="20"v:shapes="_x0000_i1044"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image024.png">是一非齐次线性方程组，<imgwidth="42"height="26"v:shapes="_x0000_i1045"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image026.png">是其任意2个解，则下列结论错误的是（）
①
<imgwidth="52"height="26"v:shapes="_x0000_i1046"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image028.png">是<imgwidth="54"height="20"v:shapes="_x0000_i1047"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image030.png">的一个解
②
<imgwidth="80"height="46"v:shapes="_x0000_i1048"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image032.png">是<imgwidth="54"height="20"v:shapes="_x0000_i1049"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image024.png">的一个解
③
<imgwidth="52"height="26"v:shapes="_x0000_i1050"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image034.png">是<imgwidth="54"height="20"v:shapes="_x0000_i1051"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image030.png">的一个解
④
<imgwidth="62"height="26"v:shapes="_x0000_i1052"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image036.png">是<imgwidth="54"height="20"v:shapes="_x0000_i1053"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image024.png">的一个解
【单选题】
设总体<imgwidth="14"height="12"v:shapes="_x0000_i1291"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image377.png">为参数<imgwidth="12"height="14"v:shapes="_x0000_i1292"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image378.png">的动态分布，今测得<imgwidth="14"height="12"v:shapes="_x0000_i1293"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image377.png">的样本观测值为0.1,0.2,0.3,0.4，则参数<imgwidth="12"height="14"v:shapes="_x0000_i1294"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image378.png">的矩估计值<imgwidth="12"height="22"v:shapes="_x0000_i1295"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image380.png">为（）
①
0.2
②
0.25
③
1
④
4
【单选题】
若<imgwidth="14"height="16"v:shapes="_x0000_i1178"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image188.png">阶可逆矩阵<imgwidth="18"height="18"v:shapes="_x0000_i1179"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image189.png">与<imgwidth="18"height="18"v:shapes="_x0000_i1180"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image190.png">相似，且<imgwidth="56"height="22"v:shapes="_x0000_i1181"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image192.png">则<imgwidth="40"height="22"v:shapes="_x0000_i1182"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image194.png">（）
①
<imgwidth="30"height="18"v:shapes="_x0000_i1183"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image196.png">
②
<imgwidth="28"height="18"v:shapes="_x0000_i1184"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image198.png">
③
<imgwidth="18"height="18"v:shapes="_x0000_i1185"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image190.png">
④
<imgwidth="26"height="22"v:shapes="_x0000_i1186"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image201.png">
【单选题】
设<imgwidth="83"height="25"v:shapes="_x0000_i1163"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb09.files/image233.png">则下列式中不成立的是（）
①
<imgwidth="46"height="21"v:shapes="_x0000_i1164"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb09.files/image235.png">
②
<imgwidth="49"height="21"v:shapes="_x0000_i1165"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb09.files/image237.png">
③
<imgwidth="84"height="27"v:shapes="_x0000_i1166"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb09.files/image239.png">
④
<imgwidth="87"height="41"v:shapes="_x0000_i1167"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb09.files/image241.png">
【单选题】
设随机变量X的分布函数为<imgwidth="36"height="21"v:shapes="_x0000_i1107"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image108.png">，下列结论中不一定成立的是（）
①
<imgwidth="69"height="21"v:shapes="_x0000_i1108"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image132.png">
②
<imgwidth="73"height="21"v:shapes="_x0000_i1109"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image134.png">
③
<imgwidth="80"height="21"v:shapes="_x0000_i1110"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image136.png">
④
<imgwidth="36"height="21"v:shapes="_x0000_i1111"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image108.png">为连续函数