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问题 选择题

A、B、C、D、E均含有同一种短周期元素，其中A是单质，B常温下是气态氢化物，C、D是氧化物，E是D和水反应的产物．下表所列各组物质中，物质之间通过一步反应就能实现如图所示转化的是（　　）

物质编号物质转化关系ADE
①SiSiO2H2SiO3
②N2NO2HNO3
③SSO3H2SO4
④NaNa2O2NaOH

A．②③

B．②④

C．①③④

D．①②③④

答案

①Si的氧化物只有二氧化硅，二氧化硅不溶于水，不与水反应，不能一步得到硅酸，故①错误；

②若A为氮气，与氢气化合生成氨气，与氧气反应生成NO，NO与氧气反应生成二氧化氮，二氧化氮与水反应生成硝酸，符合题意，故②正确；

③若A是S单质，与氢气化合生成硫化氢，与氧气反应生成二氧化硫，二氧化硫再与氧气反应生成三氧化硫，三氧化硫与水化合生成硫酸，符合题意，故③正确；

④若A是钠，则B为氢化钠，为固态，且NaH不能反应生成氧化钠，不符合题意，故④错误；

故选A．

阅读理解

Mary didn’t understand such sentences as“She is blue today”，“You are yellow”，“He has a green thumb”，“He has told a white lie”and so on．And she went to the teacher Mrs James for help．

Mary：Mrs James，there is a colour in each of the sentences．What do they mean?

Mrs James：In everyday English，Mary，blue sometimes means sad，yellow afraid．A person with a green thumb grows plants well and a white lie is not a bad one．

Mary：I’m afraid I don’t understand them a11．Would you give me an example for“a white lie”?

Mrs James：Certainly．Now I just give you some cakes．In fact you don’t like it，but you don’t want to let me know it．Instead you say，“No，thanks．I’m not hungry．”That’s a white lie．

Mary：It sounds very interesting．Thanks very much．

Mrs James：You are welcome．Colours are meaningful．I think you will meet more sentences like these in the future．Please come to me if you have any questions．

小题1:Blue sometimes means sad in________English．

A．good

B．spoken

C．usual

D．poor小题2:I don’t have a green thumb，so all my plants________．

A．die off

B．grow well

C．look nice

D．are good小题3:David is yellow and he is________to climb the tall tree!

A．happy

B．clever

C．brave

D．afraid小题4:He didn’t like me to know________of the accident．He told me a white lie at last．

A．the reason

B．the true story

C．the meaning

D．the answer小题5:He is ________today．He is told that his father is seriously ill．

A．blue

B．yellow

C．green

D．white
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单项选择题

一个三角地带，在三个边上植树，三个边的长度分别为156米、186米、234米，树和树之间的距离是6米，三个角上都必须栽一棵树，问共需多少棵树（）

A．93

B．95

C．96

D．99
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