问题 填空题

有两包白色粉末,分别是K2CO3和NaHCO3,请你写出2种不同的鉴别方法。

(1)_______________________________________。

(2)_______________________________________。

答案

(1)取两种少许待检粉末于试管中,分别加热,有CO2气体产生的是NaHCO3

(2)取两种粉末进行焰色反应实验,透过钴玻璃能够观察到紫色火焰的是K2CO3(或:取两种少许待检粉末于试管中,同时分别在两支试管中加入1mL稀盐酸,放出气体速度快的是NaHCO3

阅读理解

Thinking is something you choose to do as a fish chooses to live in water. To be human is to think. But thinking may come naturally without your knowing how you do it. Thinking about thinking is the key to critical(批判性的)thinking. When you think critically, you take control of your thinking processes(过程). Otherwise, you might be controlled by the ideas of others. Indeed, critical thinking is at the heart of education.

The word "critical" here has a special meaning. It does not mean taking one view against another view, as when someone criticizes another person for doing something wrong. The nature of critical thinking is thinking beyond the easily seen—beyond the pictures on TV, the untrue reports in the newspapers, and the faulty reasoning (错误的推理).

Critical thinking is an attitude as much as an activity. If you are curious about life and desire to dig deeper into it, you are a critical thinker; if you find pleasure in deep thinking about different ideas, characters, and facts, you are a critical thinker.

Activities of the mind and higher-order reasoning are processes of deep and careful consideration. They take time, and do not go hand in hand with the fast speed in today's world, fast foods, instant coffee, and self-developing film. If you are among the people who believe that speed is a measure of intelligence, you may learn something new from a story about Albert Einstein. The first time Banish Hoffman, a scientist, was to discuss his work with Albert Einstein, Hoffman was too nervous to speak. But Einstein immediately put Hoffman at ease by saying, "Please go slowly, I don't understand things quickly."

小题1:Critical thinking is important to us because if we do not think critically,__________.

A.it will be hard for us to think naturally and fast

B.we will follow the ideas of others naturally

C.we might be controlled by other people's ideas

D.we might be fooled by other people's ideas小题2:If you are a critical thinker, you will________.

A.criticize other people for their mistakes

B.trust the reports in the newspapers

C.take one view against another view

D.think deeply about different ideas小题3:In the last paragraph, "something new" suggests that________.

A.the smarter you are, the faster you do things

B.intelligence is not decided by speed

C.speed can improve intelligence

D.the faster you do things, the smarter you become小题4:What would be the best title for the passage?

A.Understanding Critical Thinking

B.Thinking and Critical Thinking

C.Thinking Natural and Human

D.Thinking Fast Means Intelligence

名词解释