问题 选择题

向盛有Z溶液的洗气瓶中先通入气体X,生成沉淀;再通入过量气体Y,沉淀溶解。下列各组物质中,符合以上现象的是(   )

 XYZ
ASO2NO2BaCl2溶液
BCO2NH3CaCl2溶液
CNH3HClAlCl3溶液
DCO2HClNa2SiO3溶液

答案

答案:C

题目分析:A中SO2和氯化钡不反应,没有沉淀生成,A错误;B中CO2和氯化钙溶液不反应,没有沉淀生成,B错误;C中氨气通入到氯化铝溶液中生成沉淀氢氧化铝,进入盐酸,氢氧化铝溶解,C正确;D中CO2通入到硅酸钠溶液中生成沉淀硅酸,但硅酸不能溶解在盐酸中,D错误,答案选C。

点评:该题是基础性试题的考查,试题基础性强,侧重对学生基础知识的巩固与训练,难度不大。该题的关键是记住有关物质的性质和转化,然后灵活运用即可。

多项选择题
阅读理解

阅读理解。 

     Along the river banks of the Amazon and the Orinoco there lives a bird that swims before it can fly, flies

like a fat chicken, eats green leaves, has the stomach of a cow and has claws (爪) on its wings when young.

They build their homes about 4.6m above the river, an important feature (特征) for the safety of the young.

It is called the hoatzin.

      In appearance, the birds of both sexes look very much alike with brown on the back and cream and red

on the underside. The head is small, with a large set of feathers on the top, bright red eyes, and blue skin. Its

nearest relatives are the common birds, cuckoos. Its most striking feature, though, is only found in the young.

     Baby hoatzins have a claw on the leading edge of each wing and another at the end of each wing tip. Using

these four claws, together with the beak (喙), they can climb about in the bushes, looking very much like

primitive birds must have done. When the young hoatzins have learned to fly, they lose their claws.

     During the drier months between December and March hoatzins fly about the forest in groups of 20 to 30

birds, but in April, when the rainy season begins, they collect together in smaller living units of two to seven

birds for producing purposes.

1. What is the text mainly about? [ ]

A. Hoatzins in dry and rainy seasons.

B. The relatives and enemies of hoatzins.

C. Primitive birds and hoatzins of the Amazon.

D. The appearance and living habits of hoatzins.

2. Young hoatzins are different from their parents in that _____. [ ]

A. they look like young cuckoos

B. they have claws on the wings

C. they eat a lot like a cow

D. they live on river banks

3. What can we infer about primitive birds from the text? [ ]

A. They had claws to help them climb.

B. They could fly long distances.

C. They had four wings like hoatzins.

D. They had a head with long feathers on the top.

4. Why do hoatzins collect together in smaller groups when the rainy season comes? [ ]

A. To find more food.

B. To protect themselves better.

C. To keep themselves warm.

D. To produce their young.