城市环境问题有哪些

有红,黄,蓝,绿四种颜色的玻璃球共30个,其中红色的8个,黄色的9个,蓝色的7个,绿色的6个.一次至少取出多少个玻璃球,才能保证一定有一个红色的?一次至少取出多少个玻璃球,才能保证每个颜色 有25个玻璃球,分为红,黄,蓝三种颜色,红色的玻璃球的个数是黄色的1/6,蓝色玻璃球最少有多少个?要有算式 含有八的诗句 含有五和八的词语 八个含有动物的词语比如：狐假虎威,鸡飞狗跳 一个4小时的路程 英语怎么说 含数字一道八的词语虽知道啊,谢谢! 小刚和小强在一起玩,小刚说,我们玩一个游戏吧,这个袋中装有黄白两种颜色的球各一个,它们除了颜色外都相同,任意摸一个球,摸出后再放回袋中,如果两次摸到的都是同种颜色的球,你就获胜, 一个7天的旅程 用英语怎么说 《守望——》半命题600字作文 以守望为话题的作文,800字, 以告别或守望为题目的作文 800字 急 守望为话题的作文,500字,不用太好的.一般般的 有一盒玻璃球,颜色有红、黄、绿三种,约400颗,其中红色球占总数的1/4,黄球占总数的n/9,绿球的数量不是 有同样大小的红黑黄玻璃球共72个,按1个红球,2个黑球,3个黄球的顺序排列.三种颜色的玻璃球各占总数的几分之几?第64个玻璃球应该是什么颜色? 英语翻译2.她走路去那儿要花半个小时.It ___ ___ half an hour ___ ____ there. 1.-I am sorry to tell you that you should not smoke here .Please look at the sign.-Oh,I am sorry .I ___ it .A.do not notice B.did not notice C.will notice D.have not noticed2.Mount Huang is ___ a beautiful place that ___ many people visit it every ye I'm very sorry to tell you that!but I have to.For I love you!in the past,now and for the future(maybe).I have thought for a long time,thinking that this is the best idea for you or me.Now,you and me seem to be too young to know something.These days,I i am sorry to tell you that i ____on the playgroundA.forget your booksB.forgot your books behind C.have left your books alone D.left your books behind 我选择了C.答案是D 求解~~ I am sorry to tell you that you are completely wrong为什么是completely而不是complete?不是be+adj吗? I am sorry to tell you that the book you askedfor is not ____.They say it is sold out.a.approachable b.sufficient c.comprehensible d.available 38的英语单词怎么写? 38天用英文怎么说 38.5℃用英语怎么读 38英语翻译 英语 打出来 38 英语38题 don't do that again,sorry ,I ()do that again中填won't还是can't Don’t do that again .Shame on you.A、Sorry I won't .B、OK.I won’t 又是一道英语题——Don't do that again!——Sorry,____ A.I won't B.I will C.I do D.I don't 关于墙的作文是虚拟的“墙”,不是实际生活中的墙 Don't do that again you should fllow the rules .__________ A.sorry I don 't B .ok i won't接上面：C.sorry won't D.All right i won't