Ifyoureadacloc的精选

问题详情：短文填空。根据下面短文内容，在短文的空格处填上一个恰当的词，使短文完整、通顺。  Ifyoureadaclock,youcanknowthetimeofday.Buthowdidtheearlypeopleknowaboutthetime?  Wecannotseeorheartime.Weknowito...