北京和呼和浩特相距660千米. 一列火车从呼和浩特开出,每时行驶48千米; 另一列火车从北京开出,每时行驶72千米.两列火车同时开出,相向而行,经过几时相遇?两车相遇时,从北京开出的火车比从呼和浩特开出的火车多行了多少千米?
解:660÷(48+72)
=660÷ 120
=5.5(小时)
答:经过 5.5 小时相遇.
72× 5.5﹣48× 5.5
=396﹣264
=132(千米)
答:两车相遇时,从北京开出的火车比从呼和浩特开出的火车多行了132千米
暂无解析
“Early to bed ,early to rise ”makes a man healthy, wealthy and wise.It's good for the body.This is an old saying . Have you heard of it before? It means that we must go to bed early at night,and get up early in the morning.Then we shall be healthy.We shall also be rich and clever.That is true .The body must have enough sleep to be healthy.Children of young age should haveenough sleep ,or they can't do their work very well. They will not be wise and they may not become。wealthy! .The body also needs exercise: walking, running, jumping, swimming, playing games and all other。exercise .Exercise keeps the body strong. Exercise also helps the blood to move around inside the.body .This is very important.Our blood takes food to all parts of our body.The head also needs.blood .Exercise helps us to think better.
根据短文内容 ,回答问题.
1.What does “early to bed .early to rise ”mean?
2.What must the body have to be healthy?
3.What will happen to Children of young age who don't have enough sleep?
4.What keeps the body strong?
5.What takes food to all parts of our body?