A from one end.At this moment the distance of AB is 1/7 of the total length.啥意思明天就要交,
问题描述：
A from one end.At this moment the distance of AB is 1/7 of the total length.啥意思
明天就要交,
答
A从一个端点出发。这个时候，AB之间的距离是总距离的1/7.
答
然后从另一头标记A,此时AB线的距离是整个长度的1/7.