问题 阅读理解

阅读理解

     While I was waiting outside my wife's office building for her to get out of work.I saw a bum (流浪乞丐) coming my way.

     "I hope he won't ask me for any money,  " I thought.

     He came and sat in front of the bus stop.After a few minutes he spoke."That's a very pretty car,  " he

said.He was in rags,  but he had an air of dignity (尊严) about him.

     I gave him a smile and continued cleaning my car.

     He sat there quietly as I worked.The expected asking for money never came.As the silence between

us widened,  it seemed that a voice inside me said,  "Ask him if he needs any help."

     "Do you need any help?" I asked.

     He answered in three simple but meaningful words that I shall never forget.We  often look for wisdom

in great men and women,  and we expect it from those of higher learning and achievements.I expected

nothing but an outstretched (伸出的) dirty hand from him,  but he said three words that shook me.

"Don't we all?" he said.

     I_was_feeling_high,  successful and_important above_a_bum_in_the_street,  until those three words

hit me like a shot.

     Don't we all?

     I needed help.Maybe not for a bus fare or for a place to sleep,  but I needed help.I reached in my

wallet and gave him not only enough for a bus fare,  but enough to get a warm meal and shelter for the

day.Those three little words still ring true.No matter how much you have,  you need help,  too.No matter

how little you have,  no matter how loaded you are with problems,  even without money or a place to

sleep,  you can give help.

     Maybe God looked down,  called an angel,  dressed him like a bum,  and then said,  "Go to that man

cleaning the car.That man needs help."

     Don't we all?

1. The writer was near the bus stop________.

A. to meet the bum  

B. to wait for his wife

C. to wait for a bus  

D. to clean his car

2. At the sight of the bum,  the writer________.

A. asked him if he needed any help

B. hoped to give the bum some money

C. wished the bum not to ask him for money

D. pretended to be cleaning his car

3. The underlined part in the passage means "________".

A. I thought I'm better in any way than the bum

B. I felt the bum is as good in some ways as I am

C. I felt I liked the bum very much

D. I thought I should respect the bum

4. What does the story mainly tell us?

A. Those who are poor are in greater need of help.

B. Anybody should give help to others.

C. Poor as a man may be,  he has dignity.

D. Whatever we are,  we need help.

答案

1-4: BCAD

问答题

某校化学研究性学习小组的同学对一包因敞口放置已部分变质的氢氧化钠产生了兴趣,想通过实验测定其中碳酸钠的质量分数,请参与他们的探究过程.

提出问题:样品中碳酸钠的质量分数是多少?

知识准备:

(1)氢氧化钠不能敞口放置的原因是:①______:②______.

(2)判断氢氧化钠是否变质的方法之一是向样品中加盐酸,反应的化学方程式是:______、______.

(3)判断氢氧化钠是否变质的另一种方法是将样品溶于水,再向样品中加澄清石灰水,看是否变浑浊,反应的化学方程式是:______.

(4)向氢氧化钠和碳酸钠混合物中加入盐酸时,盐酸先与氢氧化钠反应,再与碳酸钠反应;

设计方案:

甲组同学:称取16.40g样品,放入足量的盐酸直到反应停止,共收集到4.40g二氧化碳.(设计思路:根据样品与盐酸反应生成二氧化碳的质量求出碳酸钠的质量,再计算样品中碳酸钠的质量分数.)

乙组同学:称取16.40g样品,加水配成溶液,向溶液中加入过量的澄清石灰水.过滤、洗涤、干燥,共得到白色沉淀10.00g.(设计思路:根据样品与石灰水反应生成沉淀碳酸钙的质量,先求出碳酸钠的质量,再计算样品中碳酸钠的质量分数.)

解决问题:

(1)乙组同学判断石灰水是否过量的方法是______;

(2)根据两组同学的实验结果,请你帮助他们计算出样品中碳酸钠的质量分数:______.

交流与反思:

在交流时,老师问同学们“能否用上述实验所得的数据计算出样品中氢氧化钠的质量分数”,甲乙两组的同学都一致认为可以.但小明思考后,觉得甲、乙两种方案都不妥,理由是:______;

小明又重新设计新方案:

设计方案:

先用电子秤准确称取16.40g变质的NaOH样品放入锥形瓶中,用电子秤秤得锥形瓶及样品的总质量为51.40g,再把175.00g 7.3%稀盐酸平均分成7份依次加入样品中,每次充分反应用电子秤秤得锥形瓶及所盛物质的质量,实验数据记录如下:

加入盐酸的次数第一次第二次第三次第四次第五次第六次第七次
锥形瓶及所盛物质的总质量76.40101.40126.40151.40174.20197.00222.00
解决问题:

请根据上述实验数据,计算样品中氢氧化钠的质量分数为______.(不要求写计算过程)

问答题 简答题