题目

听对话,回答问题。 （1） Why did the man go to Beijing? A . To do business. B . To have a holiday. C . To see his parents. （2） What did the man do in Beijing? A . He met his friends. B . He went to the Summer Palace. C . He watched Beijing Opera. 答案：B C 已知人体皮肤的表面积约1.5 m2.那么在1个标准大气压下1.5 m2 的面积上受到的大气压力为________N．人体并没有被压扁，是因为____________________的缘故．(一个标准大气压为1.0×105 Pa)