下列四个命题中假命题是( )
A．对角线互相垂直的平行四边形是菱形
B．对角线相等的平行四边形是矩形
C．对角线互相垂直平分且相等的四边形是正方形
D．对角线相等的四边形是平行四边形
答案：D
题目分析：根据菱形、矩形、正方形、平行四边形的判定方法依次分析各选项即可作出判断.
解：A、对角线互相垂直的平行四边形是菱形，B、对角线相等的平行四边形是矩形，C、对角线互相垂直平分且相等的四边形是正方形，均为真命题，不符合题意；
D、对角线相等的四边形也可能是等腰梯形或矩形，故为假命题，本选项符合题意.
点评：特殊四边形的判定方法是初中数学的重点，贯穿于整个初中数学的学习，是中考中比较常见的知识点，一般难度不大，需熟练掌握.
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song My Deskmate, has been sent to jail (监狱) and will 1______ there for six months for drunk driving. "I've 2______ to say for myself and I'm willing to be punished (惩罚)," he said when he was standing in the 3______."What I want to say is that I feel 4______ for what I've done. I thought alcohol (酒精)could bring me freedom but never realized drunk driving could 5______ away others' freedom. And now I've 6______ my own freedom because of drinking. I'll obey the new road safety 7______ and I want to be a life-long volunteer in persuading (劝说) others not to drive after drinking." Anyone who drives after drinking doesn't think much of human life. If Gao had cared, he would have left his car parked outside the restaurant and took a 8______ home, and he would have thought about a road killer he would become. It's fair to say that his behavior can not be 9______ in modern society. Gao may not have killed anyone, but by choosing to drive a car while under the influence of alcohol, he and the large number of others who do the same have 10______ the dangerous decision that may possibly hurt other people. | |