编者：常言说：“纸上得来终没浅，给知此事要躬行．”学了理论，就要实践，才能获得真矢炎热的夏天，小明和小林到小华家找凉开水（下面简称‘水’）喝，只见小华把仅有的小半杯水倒入一个贴有宝葫芦字样的塑料瓶A中，如图三所示，不一会儿就有水源源不断地从管口流出，倒入的 Editor: As the saying goes: “The paper will never come to light, and you must know how to do this.” After learning the theory, it is necessary to practice in order to obtain the true summer heat. Xiao Ming and Xiao Lin went to Xiao Hua to look for cool water (hereinafter referred to as “Water”) Drink, I saw Xiaohua pour the only small half of the water into a plastic bottle labeled “Gourd Pouch”. As shown in Figure 3, water will flow from the nozzle in a short period of time. Poured