问题 选择题

下列说法正确的是

①NH3的水溶液能导电,故NH3是电解质  ②向含有BaCl2和NaOH的混合溶液中通入少量的二氧化硫气体,有白色沉淀生成   ③101 KPa、150℃时,agCO和H2的混合气体在足量的O2中完全燃烧,将燃烧后的产物通入足量的Na2O2固体后,Na2O2增重ag ④碱性氧化物一定是金属氧化物  ⑤22.4L的CO气体和28g N2所含的电子数相等  ⑥根据分散系是否具有丁达尔效应将分散系分为溶液、胶体和浊液   ⑦为测定熔融氢氧化钠的导电性,可在瓷坩埚中熔化氢氧化钠固体后进行测量   ⑧氧化还原中,有一种元素被氧化,一定有另一种元素被还原

A.②③④

B.②④⑦⑧

C.①⑤⑥⑦

D.③⑤⑥⑧

答案

答案:A

①错,NH3是非电解质;②正确,在碱性溶液中可以生成亚硫酸钡沉淀;③正确,根据过氧化钠与水、二氧化碳气体的反应可得Na2O2增重的质量即为反应的CO和H2的混合气体的质量;④正确,⑤错,未指明是标准状态;⑥错,根据分散质粒子直径的大小可将分散系分为溶液、胶体和浊液;⑦瓷坩埚中的成分中有二氧化硅,可与熔融氢氧化钠反应;⑧错,只能说有元素被氧化,一定有元素被还原,可以是同种元素,也可是不同种元素;

选择题
阅读理解

阅读理解。

     The summer I was ten, my mother decided to bring us to the world of art. My brother and I were not

very excited when we realized what my mother meant. What she meant was not that we could take drawing

classes or painting classes but that we would have to spend one afternoon a week with her at the Fine Arts

Museum. Before each visit to the museum, she made us read about artists and painting styles (风格). It was

almost as bad as being in school. Who wants to spend the summer thinking about artists when you could be

with your friends at the swimming pool?

     First we had to read about ancient Egyptians (古埃及人) and their strange way of painting faces and then

go to look at them at the museum. My 12-year-old brother thought this was so funny, but I was not interested.

Later we had to learn about artists in the Middle Ages who painted people wearing strange long clothing. We

had to look at pictures of fat babies with wings and curly (鬈曲的) hair and with no clothes on flying around

the edges of paintings. I certainly couldn't see what was so great about art.

     On our last visit to the museum, something happened when I saw a painting by a woman called Mary. In it,

a woman was reading to a child. The colors were soft and gentle, and you could tell by the mother's expression

how happy she was just to be with the child. I couldn't stop looking at this painting! I wanted to see every

painting Mary had ever made! It was really worth looking at so many paintings to find a painter who could

interest me so much.

1. The aim of the mother's plan was to _____.

A. take them to visit the museum

B. introduce them to the world of art

C. ask them to read about artists

D. show them different painting styles

2. What was the writer's experience in the museum before the last visit?

A. She came to feel her mother's love.

B. She liked many paintings.

C. She hardly enjoyed herself.

D. She could understand the pictures of fat babies.

4.  What was the writer's experience in the museum before the last visit?

A. She came to feel her mother's love.

B. She liked many paintings.

C. She hardly enjoyed herself.

D. She could understand the pictures of fat babies.

5. From the text, we can see _____.

A. the importance of curiosity

B. the effect of art

C. the value of learning

D. the power of family education