问题 选择题

某班四个小组进行辩论比赛,赛前甲、乙、丙三位同学预测比赛结果如下:

甲说:“第二组得第一,第四组得第三”;

乙说:“第一组得第四,第三组得第二”;

丙说:“第三组得第三,第四组得第一”;

赛后得知,三人各猜对一半,则冠军是

A.第一组

B.第二组

C.第三组

D.第四组

答案

答案:B

题目分析:因为三人都猜对了一半,假设甲说的前半句正确,来看看后面的说法有没有矛盾,有矛盾就是错误的没矛盾就是正确的.

假设甲说的“第二组得第一”是正确的,那么丙说的“第四组得第一”是错误的,

“第三组得第三”就是正确的,那么乙说的“第三组得第二”是错误的,

“第一组得第四”是正确的,这样三人都猜对了一半,且没矛盾.

故猜测是正确的.

故选B.

点评:此类问题是初中数学的难点,解题关键往往假设一个正确或错误,来推看看有没有矛盾.

单项选择题
阅读理解

阅读理解。

     BEIJING, Nov. 30 - The Bird's Nest may have been built for last year's Summer Games but Beijing's

Olympic stadium will soon be aiming at fans of winter sports.

     As temperatures have begun to drop in recent weeks, so too has the number of visitors to the

80,000-seater venue, which cost 3.6 billion yuan ($527 million) to build.

     And, fearing another harsh (寒冷的) winter, National Stadium Co Ltd, which owns the Bird's Nest,

yesterday planed to spend 50 million yuan on a "snow festival".  

     From Dec 19, visitors will be able to pay 120 yuan to enjoy skiing and snowboarding, among other

things, on its newly constructed slopes.

     The stadium owners expect to attract more than 20,000 visitors a day - twice as many as it currently

does-during the two-month festival, which will include events for both the Western and Chinese new years.

     Officials revealed it would take just 5,000 visitors a day to cover the costs of the project.

     "It's not a bad idea. You can ski on man-made snow in Dubai, so why not here?" said Heiko Grasse, a

tourist from Germany, yesterday.

     Famous outdoor equipment makers and local brands are in talks over sponsorship for the event, the

Bird's Nest owners said yesterday, while the capital's television network will also provide 500 hours of

coverage.

      "The Bird's Nest will not have a cold winter again," Wu Jingjun, the new president of National Stadium

Co Ltd, told China Daily yesterday. "We will create seasonal events almost every month from now on with

assistance from the government and, importantly, the public."

      Yang Cheng, a newly appointed vice-president of National Stadium Co Ltd, said the snow festival would run

for five consecutive winters if successful.

1. How many people visit The Bird's Nest a day before the"snow festival"?

A. About 80,000.

B. About 20,000.

C. About 10,000.

D. About 5,000.

2. Which of the following is TRUE according to the text?

A. The"snow festival" will attract more visitors from China than the Western countries.

B. People aren't allowed to visit The Bird's Nest before Dec 19.

C. The"snow festival" would run for at least five winters.

D. More than 2.4 million yuan a day is expected to be made in the"snow festival".

3. What does Wu Jingjun mean by saying"The Bird's Nest will not have a cold winter again"?

A. The Bird's Nest will be kept at high temperatures in winter.

B. Winter Olympic Games will be held in The Bird's Nest.

C. The"snow festival" will provide many events in winter.

D. The Bird's Nest will get much more assistance from the government.

4. Which of the following may NOT be included in the"snow festival" events?

A. A football game.

B. Skiing.

C. Snowboarding.

D. A New Year's Party.