问题 选择题

下列说法正确的是

A.pH=7的溶液一定是中性溶液

B.能自发进行的化学反应,不一定是△H<0、△S>0

C.白色污染、绿色食品中的“白”“绿”均指相关物质的颜色

D.Ksp不仅与难溶电解质的性质和温度有关,而且与溶液中的离子浓度有关

答案

答案:B

正确答案:B

A、不正确,pH=7的溶液,H浓度为10-7mol/L,无法确定是不与OH浓度相等,不一定呈中性;

B、正确;只要△H―T△S<0就是自发反应;

C、不正确,绿色食品是在无污染的生态环境中种植及全过程标准化生产或加工的农产品,严格控制其有毒有害物质含量,使之符合国家健康安全食品标准,并经专门机构认定,许可使用绿色食品标志的食品。

不正确,Ksp只与难溶电解质的性质和温度有关,与溶液中的离子浓度无关。

单项选择题 A1/A2型题
阅读理解

阅读理解。

     One bitterly cold day, a snowstorm blew into our area. Needing firewood, I quickly set out with my best

friend, Bruce, to took for a tree to cut down. I was glad to have Bruce along with. Cutting down a tree in a

snowstorm can be dangerous. So it was important to have a friend who could warn me of danger.

     When I chose a big 23-meter-tall tree and prepared to cut it down,my best friend suddenly warned me,

"Don't cut down that tree! It's too close to the power line!" I wasn't sure about it. So I decided to disregard

his warning. I wanted to finish the job quickly and go home. So I began cutting down the tree. When the tree

fell, there was no longer any doubt whether my friend was right.

     The tree caught the power line, bringing it to the ground. I considered cutting the tree off the line. After

all, electricity can't travel through wood, so I could safely remove the tree. As I reached out my finger to touch

the tree, pain ran up my arm and through my head. I was shocked!

     After I returned home and told my mother what had happened, she quickly called the power company.

Workers from the power company soon arrived on the scene. One of them asked if 1 had touched the tree,

and when I told him I had, his face turned pale. 

     "You should have been killed," he said.

     So why am I still alive? It was my boots that saved my life.

     Within two hours, the workers removed the tree. Soon the snowstorm calmed down-but not my mother.

     Even though she was glad I wasn't hurt, my mother was still serious about me. After all, I shouldn't have

brushed off my friend's warning.

     Through this experience,I learned it's important to listen to people who offer a different perspective. Taking

the time to listen might actually save a lot of time and trouble. It certainly would have kept me from getting the

"shock of my life".

1. The underlined word "disregard" in the second paragraph means "_____". [ ]

A. pay no attention to

B. take notice of

C. consider

D. follow

2. In spite of Bruce's warning,the author still cut down the tree because _____. [ ]

A. he was sure there would he nothing to happen

B. he wasn't sure if Bruce was right and was anxious to go home

C. he didn't hear his friend's warning at all because of the blowing wind

D. he knew electricity can't travel through wood

3. Which of the following statements is NOT true according to the passage? [ ]

A. But for his boots, the author would have died.

B. The author regretted having brushed off his friend's warning.

C. The author knew nothing about electricity.

D. When the tree was cut down,the author realized his friend was right.

4. The author wrote the passage mainly to _____. [ ]

A. give an account of one of his terrible experiences

B. make us know it's important to listen to people who offer a different perspective through his experience

C. tell us not to cut trees down any more

D. remind us to be careful while working