题目

两个物体A、B，各自重力之比是5:3，置于同一水平面时，对水平面产生压强之比是2:3，则它们与水平面的接触面积之比是_______。 答案：【答案】5:2【解析】(1)∵水平面上压力等于物体自身的重力，∴F甲:F乙=G甲:G乙=5:3；(2)∵p=，∴S=，∴它们与水平面的接触面积之比： = = ==.Dear Aunt, I am unhappy now, and I don’t know how I should do.         1            Mary and I got to know each other through English                2 _____ ___ chat-room.. Since then, we have had chatted online almost         3 ____ __ __ every night. We have many in common as we are both               4 ____ __ __ girls at the same age. We would like to tell each other many        5 _________ things which are kept secretly to others. I will feel                     6 ______   uncomfortable unless I can’t find her online.                             7 _____    Besides, she told me two days ago that she would go                 8 ____    _ abroad soon. She insisted that she would get good education      9 _______ _ .abroad than at home. I know it is wrong for her to think so,      10 ____     but I don’t know how to change her mind. Would you help me ?                                 Yours, Li Lin