问题 填空题
数列{an}的通项公式为an=
1
n
+
n+1
,其前n项之和为10,则在平面直角坐标系中,直线(n+1)x+y+n=0在y轴上的截距为______.
答案

由已知,得an=

1
n
+
n+1
n+1
-
n

则Sn=a1+a2+…+an=(

2
-
1
)+(
3
-
2
)+…+(
n+1
-
n

=

n+1
-1,

n+1
-1=10,

解得n=120,

即直线方程化为121x+y+120=0,

故直线在y轴上的截距为-120.

故答案为:-120

阅读理解

Over 1,400 university students from 37 countries and regions came to China for the 2008’s WorldMUN meeting(世界大学生模拟联合国大会). The meeting was held in Peking University from January 5th to 11st, 2008.

The idea of the WorldMUN began in 1991. A group of students at Harvard(哈佛)University wanted to make a new meeting to bring together the students who were interested in the world. They wanted to discuss different problems around the world. The WorldMUN is based on understanding, compromise, learning and friendship. The first meeting was held in Poland in 1992. After that, it is held in spring every year. Last year, it was held in Scotland.

This was the first time the WorldMUN meeting was held in Asia. It was also the biggest one in history. The students came from the best universities around the world. During the five-day meeting, they did everything that people in the UN do. Though their skin colors and cultures were different, they had the same wish to make the world better.

1.The 2008’s WorldMUN meeting was held in   .

A. Scotland    B. Harvard University    C. Beijing University     D. Thailand

2.The word “compromise” in the passage means    in Chinese.

A. 友谊         B. 理解         C. 和解         D. 同情

3. Which of the following is NOT true?

A. The students want to travel around the world.

B. The students are interested in the world.

C. The students want to discuss different problems.

D. one world, one wish !

4.The best title of the passage is     .

A. The First WorldMUN Meeting     B. The WorldMUN Meeting

C. University Student               D. A warm welcome to Beijing

单项选择题