（ ）在区里的比赛中被选上,你（ ）不能高兴的过早.

我和姐姐都【参加】了区里的英语比赛
参加比赛,不能用出席

一、All right.应用平台 1.作对方建议或劝告的应答语.
例如：—Let's go and ask him.咱们去问他吧.—All right.好的.
—Shall we go home?我们回家好吗?—All right.好的.
—You'd better not smoke.你最好不要抽烟.—All right.好的.
2.作对方想法或请求的应答语.
例如：—I think it is green.我认为它是绿色.—All right.对.
—Pass her a piece of paper,please.请递给她一张纸.—All right.好的.
—Can I put my bag here?我把书包放在这儿行吗?—All right.行.
—Will you please say that again?你再说一遍好吗?—All right.好的.
二、That's all right.应用平台 1.作对方抱歉的礼貌应答语.
例如：—I'm sorry,I can't go there with you.对不起,我不能同你一起去.
—That's all right.没关系.2.作对方感谢的应答语.
例如：—Thank you very much for your help.非常感谢你的帮助.
—That's all right.别客气

Health or Wealth?
Which is more important,health or wealth?When given this question,different people have varied answers.Some insist that health plays a more important role in our life,while others see more advantages arising from wealth.
the first group of people quote the old saying "Health is above wealth" to prove their idea.they argue that,on the one hand,a strong person can do almost anything as long as he/she tries hard.On the other hand,however,rich people will not be able to enjoy the wealth if their days are numbered.
In contrast,the advocates of wealth have such arguments as follows.For one thing,wealthy people will be able to buy more healthful foods.For another,they can enjoy better facilities to improve their health.(Take my neighbor,Lao Wang,as an example.He had a heart attack and is in hospital.However,he cannot afford the expensive operation,which costs as much as 100,000 yuan.therefore,he has to lie in bed hopelessly.If he were a rich man,his life could be saved.) (括号中的部分同学们自己可以在别的文章中发挥.)
As far as I am concerned,both health and wealth are important to our life.We should try to strike a balance between them and gain wealth with a healthy body.

Nowadays, many people use phone in the library's reading space. This phenomenon not only results in an increasing noise level that disturbs the tranquility of the library, but also, it distracts others from reading and studying. This have caused many inconveniences. In my opinion, phones should be banned in library, or at least, there should be a designated area for mobile phone users. People can only make calls in that area and nowhere else. This way, the library can re-attain its peacefulness, and more people will enjoy reading and studying there.

1.知错能改,这不能不是好学生.
2.不能全部相信别人说的话.
3.区里打来紧急电话,要求我们做好防台风工作.
4.《中国少年报》、《珠海特区报》和《科学画报》这几种报刊我都爱看.

应改为：他出席了区里组织的学生田径运动会的开幕式（或闭幕式）.
或：他参加了区里组织的学生田径运动会.
愿对你有所帮助!

他参加了区里的数学竞赛

，第一次到会的有B、D、F；
第二次有A、D、E；
第三次有A、B、D．
由于，每次开会时，每个街道只要一个责任人参加，
即每次参会的人都不同街道，
所以，D与B、F、A、E不同一街道，只能与C同一街道；
第三次有A、B、D，此时可知，A与B、C、D、E不同街道，则A与F是同一街道的；
所以B只能与E是同一街道的．
故答案为：E．

宇宙飞船飞行中,飞过的空间体积等于它的横截面积*飞过的距离
而它的速度是20km/s,飞行一分钟飞过的距离是20*60=1200km=1200000m
所以飞船飞行一分钟经过的空间体积是40*1200000=48000000m³
而每立方米的体积内有一颗微尘,所以会碰到的灰尘数为48000000颗

Nowadays,many people use phone in the library's reading space.This phenomenon not only results in an increasing noise level that disturbs the tranquility of the library,but also,it distracts others from reading and studying.This have caused many inconveniences.In my opinion,phones should be banned in library,or at least,there should be a designated area for mobile phone users.People can only make calls in that area and nowhere else.This way,the library can re-attain its peacefulness,and more people will enjoy reading and studying there.

设甲班x人,乙班y人. x-4=y+4-6 ① y-12=96%(x-12) ② 由①得： x-y=2 ③ y-0.96x=0.48 ④ ③ +④,得： 0.04x=2.48 x=62 y=60

就是从剩下的8-4=4人中分别选出没有女生的（因为指定了2个）,1个女生的,2个女孩说呢过的,3个女生的,4个女生的概率相加即可
c(8,4)+c(8,3)*c(4,1)+c(8,2)*c(4,2)+c(8,1)*c(4,3)+c(4,4)

友成友成,夺冠能成!友成友成,夺冠能成! 希望对你有帮助!

用词不当,应改为：
我和小华参加了区里的奥数比赛.

2*4/(6-4)=4(小时)
10+6*4=34(千米)
甲一共走了34千米

估计是科普类的吧
买书做题
答题的时候 注意拿铅笔划出一些关键词
读题,用圆圈圈出问的是什么 比如问原因 问对错 问主旨什么的
用波浪线划出 形容词比较级最高级 限定词 专有名词 导向性的词（如显然的,可以接受的）这些词是帮助你在文中定位在哪里找答案的
如果你总是看一遍又一遍再答题一定来不及
主要靠练习 还有不要纠结于一个单词
注意每段的首句 第二句 最后一句 里面通常包含 主旨和中心
还有注意一些所谓的提示词 但是 然而 虽然 什么的 它引导的信息通常都很重要 都在这上面出题

设女生数为x,则男生数为10-x,设女生的平均分为z,根据题意有下式成立：
(10-x)*84+x*z=10*88.2
解得：z=42/x+84

60/2=30 设长为X 则宽为X-20 X为25