小朋友们,你们知道洗手池的排水管为什么是弯的?可能很多小朋友会回答,直管和弯管都能排水,而且直管可以节省材料。为什么要用弯管呢?以前,我也是这么想的。可现在,我全明白了。经过实验证实:使用直管有两大缺点:1、下水道里的臭气会顺排水管返回室内。2、顺排水管流下的残渣, Children, do you know why the drain pipe in the sink is bent? Many children may answer that both the straight pipe and the elbow pipe can be drained, and the straight pipe can save material. Why use the elbow? In the past, I think so. Now, I fully understand. After experiments confirmed: the use of straight pipe has two major drawbacks: 1, the odor in the sewer cistern will return to the room. 2, along the drain flow of residue,