直角三角形是特殊的三角形它的一____边为底，则另一个____边成了高。面积公示表示为＝____×____÷2

    This is a map of our school. There are1 buildings in our school: a library, an office building, a class building, a dinging hall and a sports hall. The library is2the left of the class building. There3many books in the library. We study in the class building, and after class, we often read books in the4. Our teachers work in the5 . This is a building6 twelve offices. Four teachers are in one office. Our school is old,7we have a big sports hall. We8 in it. What's your favourite9? Let's play it in the sports hall. I 10 my school very much. It's very good.

一质量为0.2千克的薄壁玻璃杯，容积为3×10^-4米³，底面积为2.5×10^-3米²。将杯中盛满水时，放置在一托盘上，托盘的质量为0.1千克、底面积为1×10^-2米²，托盘放在水平桌面的中央。求：
（1）杯中水的质量是多少千克？
（2）托盘对桌面的压强是多少帕？
（3）倒出1×10^-4米³的水后，杯子对托盘的压强和托盘对桌面的压强之比。