声音是沿直线传播的吗

有雨山戴帽无雨山没腰意思（少点） 有雨山戴帽, "有雨山戴帽,无雨山没腰"是何意 “有雨山戴帽,无雨山没腰”这句谚语是什么意思? 谚语 有雨山戴帽,无雨山没腰的意思 我利用周末做作业.英译汉 为什么用抽象数据类型描述数据结构,半小时内给正确答案,奖励10分,坐等 将一个长方体框架改围成正方体框架时什么不变? 有3厘米、4厘米、5厘米的小棒若干根,要做长方体正方体框架,可以做多少不同的长、正方体,每种需要多少根 英译汉短文1.3 Reading,writing,speaking and listening are closely related.Reading ability has great effect on writing,listening and speaking.These four aspects of English teaching are closely related.If English teachers in high school ignore the 英译汉－短文I was happy to hear from you.I am hoping we will learn many things about each other.I have been an equipment operator and truck driver most all my life. I have just got back one month ago from working in Iraq for 2 years. I am build 短文英译汉The Wolf and the Crane One day a wolf was eating his dinner hastily and swallowed a bone. It stuck in his throat. He tried to get it out, but he could not. Just then a crane flew down to him. “ Dear Crane!” said the wolf to 英译汉文章When his sister Nannerl was seven and Wolferl was three,Papa started teaching her to play the piano.little Wolferl could not stay away!he love hearing her play.he would sit on the floor,playing with his toys while she practised her mus 小短文英译汉Going to the TheatreIf you want to be certain of seeing a play in London,you have to book your seat in advance.You can buy your tickets either at a theatre ticket agency or at the box-office in the theatre itself.If you go in a larg MEANING:the party will take place on SUNDAY,RAIN OR SHINE the place 用 arrive in or at?she arrived _____the place with some flowers in it... 新中国成立以来共参加过几次世博会?1.10次 2.12次 3.14次 4.15次 快 焊一个正方体框架共用去6米长的钢筋,再在外面贴上铁皮做成一个无盖的正方体,至少需要1.25平方米的铁皮,这个正方体的容积是多少? 在一个仓库里堆积着若干个正方体的货箱,仓库管理员要落实一下货箱的数量,于是他想出了一个办法：将这堆货箱的三种视图画出来,则这些正方体的货箱的个数是主视图是上面最中间一个,下 What does Ted do?是什么意思最好在7:50之前告诉我答案,谢谢大家 数学题的英文怎么写 水、斤、九、天加一样的偏旁组新字 一个面积为36平方米的正方形菜地,如果把它的边长各增加12米,菜地的面积增加了多少平方米 急找辩论论据 我方:读书要博 反方;读书要精我方 读书要博Q:我方可以从哪几个角度?对方可从哪几个角度.Q:我方有利论据,对方有利论据.Q;我方易被攻破之处.对方易破之处. 高等代数中,矩阵之间等价、合同、正交相似的典范型都是对角矩阵,但...高等代数中,矩阵之间等价、合同、正交相似的典范型都是对角矩阵,但为什么相似的典范型是若当矩阵而不是对角矩阵 一块平行四变形土地如果将它的底增加8米高不变面积就增加176平方米如果将它的高增加6米,底不变,面积就增加96平方米.原平行四边形的面积是多少平方米 飞行器在地面和太空的质量有无不同 询问:怎样使乒乓球自然滑落时并且速度最慢? 我发现今天打乒乓球球反应好迟钝我打乒乓球三年,今天第一次出现这种情况,同学说球已经扣到我拍上了,我才反应过来.我也觉得有种力不从心的感觉.同学说这可能是大脑缺氧,我这到底是怎 一个时钟的分针长9厘米,它从8点整走到8点20分,这个分针扫过的面积有多大 “家访”的英语怎么说? sleeping on the bench