问题 填空题

(2011年浙江嘉兴,21题)硅烷(SiH4)与甲烷的性质具有许多相似性,如在点燃

的条件下,都能燃烧生成相应的氧化物。SiH4中硅元素的化合价是 ▲ 。SiH4在空气中燃

烧生成二氧化硅和水,反应的化学方程式是                                 

答案

-4  SiH4+2O2SiO2+2H2O

分析:根据在化合物中正负化合价代数和为零和书写化学方程式的要求写配注等,进行解答.

解答:解:根据在化合物中正负化合价代数和为零,可得SiH4中硅元素的化合价为:x+(+1)×4=0,x=-4;

SiH4在空气中燃烧生成二氧化硅和水,反应的化学方程式为:SiH4+2O2SiO2+2H2O;

故答案为:-4; SiH4+2O2SiO2+2H2O.

阅读理解

Most people want to know how things are made. They honestly admit, however, that they hardly know a thing when it comes to understanding how a piece of music is made. Where a composer begins, how he manages to keep going – in fact, how and when he learns his trade – all are covered in complete darkness. The composer, in short, is a man of mystery .

One of the first things the common man wants to know about is the part inspiration plays in a composer’s work. He finds it difficult to believe that composers are not much interested in that question. Writing music is as natural for the composer as eating or sleeping for all. Music is something that the composer happens to have been born for.

The composer, therefore, does not say to himself: “Do I feel inspired?” He says to himself: “Do I feel like working today?” And if he feels like working, he does. It is more or less like saying to himself: “Do I feel sleepy?” If you feel sleepy, you go to sleep. If you don’t feel sleepy, you stay up. If the composer doesn’t feel like working, he doesn’t work. It’s as simple as that.

小题1:What would be the best title for the text?

A.Composer: a man of mystery

B.Practice makes good music

C.Relation between sleeping and music

D.Music: product of nature小题2:Most people seem to think that a composer ____.

A.finds it difficult to write music

B.considers it important to have a good rest

C.should like to talk about inspiration

D.never asks himself very simple questions小题3:The author will most probably agree that composers ____.

A.are born with a gift for music

B.are people full of mystery

C.work late at night for their music

D.know a lot about eating and sleeping

多项选择题