如图所示，贮水器的壁面上有四个盖子，直径均相等，其中盖子1、4为半球形，盖子2、3为平底，则所受到的静水总压力最大的盖子为（）。
A.盖子1
B.盖子2
C.盖子3
D.盖子4
参考答案：C
解析：
画出各个盖子的压力体，可知所有的盖子只有竖直方向的作用力，其中盖子 1、2受到的是浮力，3、4受到的是压力，压力体的体积关系为3＞4＞1＞2，根据公式户＝ρgV，盖子3受到的总压力最大。
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| Some inventions are very important. For example, the telephone allows people to communicate all over the world. The 1 lets people travel long distances in a short time. Life is much easier with these 2 inventions. Some inventions are just fun. A company in Japan has invented 3 flowers. You can listen to music that comes through real flowers. Customers in restaurants can smell the beautiful roses 4 listen to pleasant music while eating. People in the dentist's office can look at pretty lilies and listen to Mozart while having their 5 examined! There is now a vehicle that gets you around with almost no effort 6 . In fact, you drive this invention while standing on it! This vehicle runs by electricity. It 7 quite easily. When you lean forward, it moves forward, and when you lean 8 , it moves backward! A new kind of bubble liquid has been invented. If you blow bubbles 9 this liquid, they can last for several minutes! 10 are very strong. You can even pick them up and throw them around! Do you have your own ideas about inventions now? | ||||
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