问题 填空题

与往届奥运会火炬的混合燃料不同,北京奥运会火炬-“祥云”使用的燃料为丙烷,它的化学式为C3H8,这是一种价格低廉的常用燃料,在空气中完全燃烧后生成二氧化碳和水.

(1)丙烷在空气中燃烧时发生反应的化学方程式为:C3H8+5O2

点燃
______

(2)“祥云”火炬的外壳采用的是铝合金材料,请你说出使用该材料的一个优点:______.

答案

(1)丙烷燃烧生成水和二氧化碳,化学方程式为:C3H8+5O2

 点燃 
.
 
3CO2+4H2O.

(2)铝合金作为一种合金,具有合金的优良性能,其密度小,硬度大,抗腐蚀,不要生锈等特点.

故答案为:

(1) 3CO2+4H2O

(2 )轻、不易生锈、有光泽(美观)….

选择题
阅读理解

Alfred Alder, a famous psychiatrist, had an interesting experience. When he was a small boy he got off to a poor start in arithmetic. His teacher got the idea that he had no ability in arithmetic, and told his parents what she thought in order that they would not expect too much of him. In this way, they too developed the idea, “Isn’t it too bad that Alfred can’t do arithmetic?” He accepted their mistaken estimate of his ability, feeling that it was useless to try, and that he was very poor at arithmetic, just as they expected.

One day he became very angry at the teacher and the other students because they laughed when he said he saw how to do a problem which none of the other students had been able to solve.

Adler succeeded in solving the problem. This gave him confidence. He rejected the idea that he couldn’t do arithmetic and was determined to show them that he could. His anger and his new found confidence stimulated him to go at arithmetic problems with a new spirit. He now worked with interest, determination, and purpose, and he soon became extraordinarily good at arithmetic. He not only proved that he could do arithmetic, but he learned early in life from his own experience that, if a person goes at a job with determination and purpose, he may astonish himself as well as others by his ability.

This experience made him realize that many people have more ability than they think they have, and that lack of success is as often the result of lack of knowledge of how to apply one’s ability, lack of confidence, and lack of determination as it is the result of lack of ability.

小题1:Alfred gained confidence in learning arithmetic_______.

A.after he managed to find a solution to a difficult problem

B.after his teacher made his parents know his ability in arithmetic

C.after he grew up and became famous

D.after his parents gave him encouragement小题2:In Alfred’s opinion, if a person is unsuccessful, he may be_______.

A.slow- thinking.

B.disabled

C.self-centered

D.undetermined小题3:The last sentence of paragraph 1 implies________.

A.Alfred thought he couldn’t change others’ mind

B.Alfred agreed with the wrong judgment

C.Alfred believed it was no use learning arithmetic

D.Alfred expected that he could succeed though it was hard小题4:What can we conclude from the text?

A.Alfred has a strong determination and a firm belief

B.Others’ opinions are important

C.A person lacking in ability can still succeed

D.Alfred’s teacher and classmates will regret.