问题 填空题

碳酸钙经过高温煅烧可分解成氧化钙和二氧化碳,这也是工业上生产生石灰的化学原理.称取两份碳酸钙,一份跟足量的稀盐酸反应,另一份在高温条件下充分煅烧,若要放出等质量的气体,则两份碳酸钙的质量比为______.

答案

不论是高温分解制取二氧化碳,还是与盐酸反应制取二氧化碳,二氧化碳中的碳元素全部来自前面的碳酸钙,根据质量守恒定律,二氧化碳的质量相等,碳酸钙的质量也应该是相等的,故答案为:1:1.

阅读理解

阅读理解。

        I am a strong believer that if a child is raised with approval, he learns to love himself and will be

successful in his own way.    Several weeks ago,I was doing homework with my son in the third grade

and he kept standing up from his chair to go over the math lines.I kept asking him to sit down, telling him

that he would concentrate better. He sat but seconds later, as if he didn’t even notice he was doing it, he

got up again.I was getting frustrated, but then it hit me.I started noticing his answers were much quicker

and accurate when he stood up.Could he be more intent while standing up?

        This made me start questioning myself and what I had been raised to believe. I was raised to believe

that a quiet, calm child was a sure way to success.This child would have the discipline to study hard, get

good grades and become someone important in life.

        Now those same people perhaps come to realize that their kids are born with their own sets of DNA

and personality traits,and all you can do is loving and accepting them.As parents,throughout their

growing years and beyond that, we need to be our kids' best cheerleaders,guiding them and helping them

find their way.    

        I have stopped asking my son to sit down and concentrate.Obviously, he is concentrating just in his

own way and not mine.We need to learn to accept our kids' ways of doing things.Some way may have

worked for me but doesn't mean we need to carry it through generations.There is nothing sweeter than

being individual and unique.It makes us free and happy and that's just the way I want my kids to live their

own life.

1. At the beginning, the author tried to keep his son seated in order to make him________.  

A. pay more attention to his study              

B. keep silent in the room

C. finish his homework on time                

D. get right answers

2. Inspired by the case of his son,the author began to doubt________.  

A.the importance of parents                  

B.the old form of education

C.the relationship between kids and their parents

D.the good grades of some kids

3. According to the passage, which of the following statements is right?

A. We should help kids correct their wrong ways.

B. Parents should study their kids’ DNA.    

C. Kids should be taught to behave themselves.

D. Parents should love and accept their kids.

4. The author has stopped asking his son to sit down because __________.

A. he has changed his traditional ideas      

B. his son wants to be unique

C. his son doesn’t follow his advice        

D. his son’s DNAis different

5. Which of the following would be the best title of the passage?

A. Study hard and you'll be successful        

B. Be friendly to your children

C. Children's success in their own style        

D. Parents' help with their children's study

问答题 简答题