问题 填空题

置换反应的通式可表示为:

请回答下列问题:

(1)若甲为黄绿色气体,单质乙能使淀粉溶液变蓝色,则该反应的离子方程式为:               

(2)若过量的单质甲与化合物A发生反应的化学方程式为: 2Al+Fe2O3Al2O3+2Fe。该反应可用于焊接铁轨,要除去反应后混合物中剩余的铝粉与生成的Al2O3所用的试剂是:       

(3)若单质甲是一种常见的金属单质,化合物B是一种磁性黑色晶体,写出该反应的化学方程式:                 

(4)若单质乙是黑色非金属固体单质,化合物B是一种优质的耐高温材料,则该反应的化学方程式为:                    

(5)硅是一种重要的半导体材料,广泛应用于电子工业的各个领域。工业上制取硅单质所用的化合物A是       ,A非常细,导光能力很强,可用作            

答案

(1)2I- + Cl2 = I2 + 2Cl-(3分)  

(2)NaOH溶液(2分)

(3)3Fe + 4H2O(g)Fe3O4 + 4H2   (3分)

(4)2Mg+CO22MgO+C(3分)

(5)SiO2  光导纤维 (各2分 )

单项选择题
阅读理解

When I was twelve years old, my family were the first black people to move into an all white part of Grand Rapids, Michigan. Many of our new neighbors weren’t very welcoming. Some of them said angrily that we should return to where we came from. The children sometimes threw stones at me .

Most of my teachers simply took no notice of me, but not Dorothy Bean, my history teacher. Miss Bean was angry at how badly I was being treated, but she didn’t say this to me. Miss Bean showed her respect for me by teaching me just like anyone else. Instead of being unnoticed, I was given a chance to show that I was clever. Miss Bean was the first teacher who ever made me think for myself. She always wanted to know what I thought about different questions. She expected me to have my own idea. Miss Bean was teaching me that thinking for oneself was the real key to education.

One day, when I was not paying attention in class, Miss Bean suddenly threw an eraser(黑板擦) at me. The eraser hit me right on the hand and sent my pencil flying. The whole class were very surprised at first, then started laughing. This event became famous in the school and, because it happened to me, the students wanted to get to know me. So that’s the story of how Dorothy Bean made me her target(靶子). However, what I want to do is express my thanks to her.

56. The author and his family were not welcomed by the local people because ____________.

A. they returned from another country     B. they have different skin color

C. they spoke a different language         D. they moved to a wrong place

57. From the end of the first paragraph we know that _____________.

A. children were more friendly to strangers

B. American schools were not safe for kids

C. children often follow their parents’ behavior

D. fighting each other is part of children’s nature

58. Miss Bean respected the author by ____________.

A. giving him special attention.

B. hitting him with an eraser.

C. giving him extra lessons.

D. treating him as one of her students.

59. To Miss Bean the most important thing for a student is to _________.

A. pay close attention to what the teacher says.

B. learn to think and have one’s own idea.

C. keep silent and unnoticed in class.

D. get special attention from the teacher.

60. Which is the writer’s attitude to Miss Bean?

A. Grateful.      B. Hateful.      C. Negative.       D. Supportive.