题目

一等比数列的项数为2n,前3项之和为64，所有项之和为偶数项和的4倍，求此等比数列的和. 答案：解：∵该数列有2n项，∴奇数项和偶数项各n项.    设奇数项之和为a1+a3+…+a2n-1=S,则偶数项之和a2+a4+…+a2n=a1q+a3q+…+a2n-1q=q(a1+a3+…+a2n-1)=qS.    由题意得S+qS=4qS,解得q=.    又∵a1a2a3=64,∴a2=4.∴a1==12.∴此等比数列所有项之和为S2n==. 翻译语篇 （5小题，计10分）What are magic words? Words like ‘thank you’, ‘please’ and ‘sorry’ can work wondersin our daily life. These polite expressions are used every day in American—amongstrangers, between friends or with family. People with good manners always communicate with others well by using these magic words.What should you do when you receive a gift for your birthday? You’d better sit downand write a thank-you letter. The words ‘ thank you’ are very important and used very often. We say them when someone hands us a letter, passes us a book, offers us a bottle of water, or lends us an umbrella.“请”是另一个重要的词，但是很多人忘记去使用它. It is not polite to ask someone for help without saying ‘please’. We are supposed to use it when we ask for something, too. It may be a book, a pen, or more milk. It may be in the classroom, at home, or at the bus stop. We can use ‘please’ to make a. request.We should also learn to say sorry.如果我们已经伤害了某个人的感情，我们应该说“对不起”.When we have told a lie and regret it, the same word should be used. Sometimeswe have forgotten something or broken a promise, so we need to explain with the word as a beginning. ‘Sorry’ is such a word that can make people forget wrongs‘Thank you! Please! Sorry!’—these words are simple but useful. Man said them long ago. We use them now. So will our kid.【1】___________________________________________________________________________【2】___________________________________________________________________________【3】___________________________________________________________________________【4】___________________________________________________________________________【5】___________________________________________________________________________