The water clock has three parts.On the left is a tank holding water.This tank has a narrow opening through which water drips into a second container,also a tank.Inside the second tank is a floating object,to the end of which is attached a long pole with an arrow.On the right is a cylinder with the numbers one to twelve written on it.As the water from the tank on the left drips into the second tank,the level rises and with it the lfoating object.This causes the arrow to move from one number to the next.One thus has a twelve hour clock.After twelve hours the second tank is emptied and the process is begun again.
中学生写作指导、写作素材、优秀作文以及有奖活动
尽在“深海网”微信公众号
版权声明
本站文章收集于互联网，仅代表原作者观点，不代表本站立场，文章仅供学习观摩，请勿用于任何商业用途。
如有侵权请联系邮箱tuxing@rediffmail.com，我们将及时处理。本文地址：http://www.15033.cn/zuowen/yyzw/gzyyzw/gyyyzw/278278.html