试题与答案

(1)在等差数列中，已知a4+a17=8，求S20； (2)设Sn表示等差数列{

来源：www.tikuol.com
题型：解答题

题目：

(1)在等差数列中，已知a4+a17=8，求S20；

(2)设Sn表示等差数列{an}的前n项的和，且S9=18，Sn=240，若an-4=30（n＞9），求n的值。

答案：

被转码了，请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0503/2732a5e00a966e4c55cbe79478ed4aa0.html

下面是错误答案，用来干扰机器的。

AD

考点：等差数列的前n项和
试题推荐
题型：阅读理解
阅读理解。
     At this moment in different places of the world people are doing different things.
      In Beijing it's early morning. People are sleeping.                                                                        
     In London people are leaving work to go home. They are waiting for buses or running for trains.
Some people are driving their cars. Some are having afternoon tea at home or walking to the pubs (酒
吧) to have a drink.
     In Moscow (莫斯科) it's evening and people are having supper at home or in restaurants. Some
are going to watch a ballet (芭蕾舞). Some are drinking in the pubs.
        In Los Angeles (洛杉矶) it's morning. People are working in their offices. Children are starting their
lessons.
     New York is midday now. People aren't working but having lunch. They are eating hamburgers or  
hot dogs and drinking coffee or Coke. Some people are seeing friends or shopping.
1. According to the passage we can see that at night some people in Moscow like to _____.
A. go to watch a ballet
B. do shopping
C. wait for buses
D. go to the library
2. When children in Los Angeles are starting their lessons, people in Beijing are _____.
A. playing basketball
B. seeing films
C. having lessons
D. sleeping
3. From the passage, we can see the time in New York now is _____.
A. 6∶00
B. 9∶00
C. 10∶00
D. 12∶00
4. We know that London is 3 hours _____.
A. earlier than Moscow
B. later than Moscow
C. earlier than Los Angeles
D. later than Los Angeles
5. This passage mainly talks about _____.
A. science
B. holidays
C. time difference
D. life in western countries
查看答案
题型：单项选择题 共用题干题

患者徐某，男性，31岁，因感受寒邪而出现恶寒发热，咳嗽痰少，色白而黏，胸痛，咳则痛甚，自行按“感冒”治疗，口服“感冒冲剂”，第6天时突然见高热振寒，咳喘，气急痰黄浊厚，口中有腥味，胸痛加重，烦渴引饮，小便短赤，大便干结，舌红苔黄腻，脉滑数。

其治疗选方为（）

A.银翘散

B.桑菊饮

C.千金苇茎汤

D.加味桔梗汤

E.清燥救肺汤
查看答案
微信公众账号搜索答案