题目

为测量大气压强的数值，王欣同学进行了如下实验，将塑料挂钩吸盘按压在光滑水平玻璃下面，挤出塑料吸盘内的空气，测出吸盘压在玻璃上的面积为S；将装适量细沙的小桶轻轻挂在吸盘下面的塑料挂钩上，如图所示，用小勺轻轻向桶内加细沙，直到塑料吸盘刚好脱落玻璃板，测出此时塑料挂钩、小桶和沙的总重力为G。 （1） 吸盘即将脱离玻璃板时，空气对塑料吸盘的压力大小是，所测大气压强的数值是； （2） 该方法所测大气压强数  阅读学校论坛上发表的5个信息材料，然后从A、B、C、D和E中，选出与信息相对应的建议。 (    )66．There are too many net bars around us. Some of my classmates often spend too much time in playing computer games and stay in the net bars all day and all night . As a result, they do worse and worse in their lessons. (     )67.Sometimes I get angry easily and shout at my friends. That makes them think I’m not being friendly to them. (     )68. I’m shy, and I’m nervous about answering the teachers’ questions. I’m afraid that I can’t get good results in my English exams. (     )69.My best friend’s birthday is coming, I want to give her something special but I haven’t got enough money and I’m not good at making things. (     )70.According to a result survey in Fuzhou, one of every five children in this city is overweight. Doctors said a big reason was that children spent long hours in front of the television. A.  Practice speaking English as much as possible and please remember “Nothing is difficult if you set your mind on it .” B.  As a Students , they mustn’t go online when it’s time for them to study. They should learn how to use the computer to get more information after school. C.  Have a balanced diet, take more exercise. D.  When your friend knows what you are thinking, I think she will be happy. A good friend never minds how much the gift costs . Write a letter to her or buy her a gift you can afford. E.  When you feel angry you should stop talking and count to ten or walk away until you feel calm.