问题 选择题

根据如图所示的实验操作图示回答问题.

(1)下列图示①、②、③、④操作中有错误的是       ,共有       处错误.

(2)若用⑤收集下列气体,从a通入气体可以收集     (填字母代号,下同);从b通入气体可以收集    

A.NH3

B.CO2

C.CH4

D.SO2

答案

(1)④;2;(2)BD;AC.

题目分析:(1)过滤操作的注意事项是:一贴二低三靠,应该用玻璃棒引流,否则液体会溅出;漏斗尖嘴    部分紧贴烧杯内壁,图示中没有紧贴,所以有二处错误;(2)从a通入气体可以收集密度比空气大的气体,二氧化碳和二氧化硫的密度都比空气的密度大;从b通入气体可以收集密度比空气小的气体,氨气和甲烷密度比空气密度小。

多项选择题
阅读理解

Today, people all over the world are moving out of small villages in the country to go and live in big noisy cities . They are moving from the peaceful hills, mountains, fields, rivers and streams of the countryside to the busy world of streets, buildings, traffic and crowds. This movement from rural areas to urban areas has been going on for over two hundred years.

In many countries, the main reason people come to live in towns and cities is work. After one or two large factories have been built in or near a town, people come to find a work, and soon an industrial area begins to grow. There is usually a residential area nearby, where the factory workers can live. The families of these workers need schools, hospitals and shops, so more people come to live in the area to provide these services—and a city grows.

  In every major city in the world, there is a business district where the big companies have their main offices. In the United States, this area is usually in the city center downtown. It is here that you can see the huge skyscraper office blocks. The people who work here often travel a long way to work each day.

  Many of them live in the suburbs of the city, far away from the industrial area and the city center. Some suburbs are very pleasant, with nice houses and big gardens. There are usually parks for children to play in and large department stores where you can buy all you need.

  But what is the future of the big cities? Will they continue to get bigger and bigger? Perhaps not. Some major cities have actually become smaller in the last ten years, and it is quite possible that one day we will see people moving out of the major cities and back into smaller towns and villages.

小题1:We can easily know that the underlined phrase “urban areas” means._____

A.areas of the countryside

B.areas of a town or city

C.areas near the countryside  

D.areas near a town or a city小题2:Why do people move to live in cities or towns?

A.Because they can live more comfortable there

B.Because they prefer noisy life to peaceful life

C.They do so mainly to find work

D.They don’t like small villages小题3:We can infer that this movement from rural areas to urban areas_______. 

A.has been going on for more than 2,000 years

B.will continue in the future

C.may not continue in the future 

D.is sure to stop