不管工作有多忙,每个星期我至少要抽出半天时间,陪儿子玩一玩既是为了让儿子有个玩伴,也是为了自己享受和儿子一起玩的快乐。有一个星期天,我跟儿子在学校的大操场放完风筝回来,路过街道时,我们看到一些工人在清理下水道。下水道的盖子被掀开了,放在一边。儿子指着那些盖子问我:“为什么下水道的盖子都是圆的而不是方的呢?”我认为儿子问的这个问题挺有意思,就提议我们爷俩共同去研究这个问题。回到家,我问儿子:“怎样才能区别圆盖 No matter how busy my work is, I have to take at least half a day each week to spend time with my son, both to let my son have a playmate and to enjoy the pleasure of playing with my son. One Sunday, my kite came back with my son at the school’s big playground. As we passed the street, we saw some workers cleaning the sewers. Sewer lid was opened, aside. The son pointed at the covers and asked me, “Why are the covers of the sewers round rather than square?” I think the question asked by my son is quite interesting, and it is proposed that we and our father jointly study the issue. When I got home, I asked my son, "How can we tell the difference?