一人坐在游艇上以30m/s的速度向山崖航行,在某处鸣笛后再过了4s听到了回声,求 发布时间:2017-05-03 08:25 │ 来源:www.tikuol.com 题型:问答题 问题: 一人坐在游艇上以30m/s的速度向山崖航行,在某处鸣笛后再过了4s听到了回声,求听到回声时距离山崖多远?(此时气温为15℃)
题型:问答题 Living with his daughter is a great ________ for the old man.[ ]A. comfort B. relieveC. relaxation D. behavior 查看答案