问题 问答题

(1)10%的甲醇(CH3OH)溶液中,氧元素的质量分数为______.

(2)一个青少年正常情况下每天约需0.8g钙.若每天从食物中得到0.6g钙,其余由钙片补充.问每天需吃含葡萄糖酸钙[(C6H11O72Ca]86%的钙片质量是多少?______.

答案

(1)假设甲醇溶液质量为m

10%的甲醇(CH3OH)溶液中,氧元素的质量分数=

m×10%×
16
32
×100%+m×(1-10%)×
16
18
×100%
m
×100%=85%

(2)根据题意,设每天需吃钙片的质量为x

x×86%×

40
430
×100%=0.8g-0.6g

x=2.5g

故答案为:(1)85%;(2)2.5g.

完形填空

阅读下面的短文,请根据短文后的要求答题(请注意问题后的字数要求)。

Dikembe Mutombo grew up in Africa among great poverty and disease. He came to Georgetown University on a scholarshipto study medicine—but Coach JohnThompson got a look at Dikembe and had a different idea. Dikembe became a star in the NBA, and a citizen of the United States. But he never forgot the land of his birth, or the duty to share his fortune with others. He built a new hospital in his old hometown in the Congo. A friend has said of this good-hearted man: "Mutombo believes that God has given him this chance to do great things."

Success and kindness

After her daughter was born, Julie Aigner-Clark searched for ways to share her love of music and art with her child. So she borrowed some equipment, and began filming children’s videos in her own house. The Baby Einstein Company was born, and in just five years her business grew to more than $20 million in sales. And she is using her success to help others—producing child safety videos with John Walsh of the National Center for Missing and Exploited Children. Julie says of her new program: "I believe it’s the most important thing that I have ever done. I believe that children have the right to live in a world that is safe."

Bravery and courage

A few weeks ago Wesley Autrey was waiting at a Harlem subway station with his two little girls when he saw a man fall into the path of a train. With seconds to act, Wesley jumped onto the tracks, pulled the man into the space between the rails, and held him as the train passed right above their heads. He insists he’s not a hero. He says: "We have got to show each other somelove."

小题1:What was Mutombo praised for? ( No more than 8 words)

小题2:What did the Baby Einstein Company do at its beginning? (No more than 7 words)

小题3:What does Julie think of her job? ( No more than 14 words)

小题4:Why was Wesley Autrey praised as a hero? ( No more than 10 words)

小题5:What does the underlined “rails” mean? ( No more than 2 words)

填空题