问题
选择题
给出以下三个命题：①对角线相等的四边形是矩形；②对角线互相垂直的四边形是菱形；
③对角线互相垂直的矩形是正方形；④菱形对角线的平方和等于边长平方的4倍．其中真命题的是（ ）
A．③
B．①②
C．②③
D．③④
答案
①错误，例如等腰梯形；
②错误，例如对角线互相垂直的等腰梯形；
③正确，符合正方形的判定定理；
④正确，符合菱形的性质．
故选D．
搜题请搜索小程序“爱下问搜题”
给出以下三个命题：①对角线相等的四边形是矩形；②对角线互相垂直的四边形是菱形；
③对角线互相垂直的矩形是正方形；④菱形对角线的平方和等于边长平方的4倍．其中真命题的是（ ）
A．③
B．①②
C．②③
D．③④
①错误，例如等腰梯形；
②错误，例如对角线互相垂直的等腰梯形；
③正确，符合正方形的判定定理；
④正确，符合菱形的性质．
故选D．
| 阅读理解。 | ||||
| The following is some information about the programs of two channels(频道). Here you can watch any program you like. | ||||
| ||||
| 1. Children would like to watch _________ on _________TV at 6:30 pm. | ||||
| A. Talk Show, Sunshine B. Talk Show, Life C. Hello Kitty, Sunshine D. Hello Kitty, Life | ||||
| 2. To improve your English, you could watch _________at _________ every day. | ||||
A. English Around the World, 18:00  B. Today’s News, 18:30 C. News in English, 19:30 D. Roman Holiday, 22:30 | ||||
| 3. Tom would watch _________at 20:10 on Life TV. | ||||
| A. Romance of the Three Kingdoms B. Lucky Winner C. Programs Next Week D. Sports News | ||||
| 4. John likes to watch news on TV. But he has to go to sleep before 23:00. How many news programs would he watch on Life TV? | ||||
| A. One. B. Two. C. Three. D. Four. | ||||
| 5. From this article, we can know_________. | ||||
| A. China Music TV is a program for old people. B. there are three programs before 19:00 on Life TV. C. there would be a movie at 23:00 on Life TV D. there are ten different programs on Sunshine TV. |