已知A={x|x为矩形}，B={x|x为菱形}，则A∩B=______．
∵A={x|x为矩形}，∴其元素的几何特征是有一个角为直角的平行四边形，
∵B={x|x为菱形}，∴其元素的几何特征是邻边相等的平行四边形，
由交集的性质，A∩B中元素的特征是有一个角是直角且邻边相等的平行四边形，这样的图形是正方形，
故A∩B={x|x为正方形}
故答案为 {x|x为正方形}
| 阅读理解。 | ||||
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| 1. Where can we see this menu? | ||||
| A. In the market. B. In the department store. C. In the post office. D. In the restaurant. | ||||
| 2. I want to have a big sandwich, a glass of orange juice and some fruit. How much are they? | ||||
| A. $ 11.50 B. $ 0.50 C. $ 2.50 D. $ 2. 00 | ||||
| 3. Which is the most expensive (昂贵的) one in the menu above? | ||||
| A. Coffee. B. Rice with chicken. C. Pizza. D. Salad. | ||||
| 4. Main courses means in Chinese ___________. | ||||
| A. 主食 B. 蔬菜 C. 牛排 D. 饮料 | ||||
| 5. What's Chez Panissh's telephone number? | ||||
| A. 57 B. 94709 C. 50 D. 5485525 |