求翻译：Lifts are very important to us. Why? Think about a tall building. Maybe it has twenty floors. Maybe it has fifty or more. Who can walk up all the stairs? Maybe people can climb them one time. Can someone climb thirty floors to an office every day? Can small children walk up to their room on the twenty-fourth floor? Can their mother and father carry food up all those stairs? Of course not.是什么意思？

待解决 悬赏分：1 - 离问题结束还有