题目

More and more teachers tend to think that teaching is really a job, so they have to devote a lot to it. A. rewarding                    B. blessing C. demanding                    D. depressing 答案：C在水平桌面上放着一个玻璃杯，水面距杯底的高度为10cm，水重为5N，玻璃杯重1N，玻璃杯的底面积是100cm2，求：（1）水对杯子底部的压强是多少？（2）杯子对桌面的压强是多少？