问题 填空题

如果半径为2和7的两个圆相切,那么这两圆的圆心距为______.

答案

当两圆外切时d=7+2=9;

内切时d=7-2=5.

所以两圆的圆心距为9或5.

单项选择题
阅读理解

阅读理解。

     On August 15th, in the women's individual all-around final of gymnastics of the Beijing 2008 Olympic

Games, Chusovitina is a shining star although she failed to win a medal eventually.

     When 33-year-old Oxana Chusovitina competes in her fifth Olympics (Beijing Olympics), she is twice

the age of most of her competitors. In addition, she has also competed in ten World Championships, three

Asian Games and three Goodwill Games. Chusovitina holds the record for the most individual World

Championships medals on a single event. She won an Olympic team gold medal as a 17-year-old in 1992.

Since then she has won a record of eight world titles.

     Her long career owes something to fate. In 2002, when her son Alisher, now aged nine, was diagnosed

with leukemia (白血病), she moved to Germany so that he could get the best possible treatment. To help

in those difficult times she kept up her training. It has paid off. But saving Alisher's life is not her only

motivation. As she recently told German media,"There is nothing in the world I enjoy more than gymnastics."

     Chusovitina was born on June 19, 1975 in Uzbek USSR. She was formerly a citizen of, and a competitor

for, the former Soviet Union (before 1993) and Uzbekistan (1993-2006). She has competed for Germany

since 2006. By the year of 2008, Chusovitina's career in gymnastics had been twenty years.

     She is one of only a handful of women to return to high-level gymnastics and international competition

after becoming a mother. Chusovitina is remarkable in her ability to remain competitive for so many years,

often in the face of great difficulty, and has been considered as a role model and an inspiration by many

people in the gymnastics community.

1. When she was 17 years old, Chusovitina won an Olympic team gold medal for _____.

A. the former Soviet Union

B. Uzbekistan

C. Germany

D. Russia

2. Chusovitina might begin her career in gymnastics in _____.

A. 1975

B. 1988

C. 1992

D. 2002

3. Chusovitina left her homeland because _____.

A. she wanted to compete in the Beijing 2008 Olympic Games

B. she wanted to serve for Germany

C. she wanted her son to get the best treatment

D. she had to face great difficulty in her homeland

4. According to the passage, Chusovitina is different from the other competitors in the Beijing 2008 Olympic

    Games because _____.

A. she is the best competitor in the games

B. she is much older than other gymnastics girls

C. she won an Olympic team gold medal when she was very young

D. she competes in order to earn money