问题 计算题

胃舒平药片可用来治疗胃酸过多症,药片的标记如图所示,其主要成分是氢氧化铝[Al(OH)3],请计算:

(1)Al(OH)3中各元素的质量比:Al∶O∶H=________(最简整数比)。

(2)医生给某患者开出服用此药的处方是:每次四片,一天三次,试计算,患者按处方服用该药片一天,理论上可中和HCl多少克?(结果保留一位小数)

答案

(1)9∶16∶1

(2)解:设理论上可中和HCl为X克

Al(OH)3+3HCl==AlCl3+3H2O

78  109.5

3克  X

78∶109.5=3克∶X

X=4.2克

单项选择题
阅读理解

Could a grizzly bear move to your neighborhood? If you live in the U.S. West, the answer may be yes. People and grizzly bears are living closer together now.

The grizzly bear is one of the largest meat-eating land animals in North America. In the early 1800s, about 50,000 grizzly bears lived there. Today there’re far fewer bears. Settlers built cities and roads where bears lived. Many bears were hunted and killed. Now only 1,200 to 1,400 grizzly bears have remained.

In and around Yellowstone National Park, grizzly bears have been making a comeback because of people’s efforts to protect them. Some bears are moving to areas where people live. People are also moving into grizzly countries.

People there have to learn how to live with their new, furry (毛皮的) neighbors peacefully. If someone leaves their barbecue grill(烤肉架)out overnight, or leaves their pet food or rubbish where a bear can get it, the bear will learn to come to their house for food. Grizzly bears that learn to eat people’s food can become dangerous, and they often have to be killed or moved. Also, it’s important not to surprise a grizzly. Besides, if you are hiking in a grizzly country, you should go with others and make a noise to make bears hear your coming and get out of the way. You may not want to invite grizzly bears to your next neighborhood party, but with a little effort, grizzly bears and people can live together peacefully.

小题1:Why does the number of grizzly bears get smaller, according to the text?

A.Settlers’ buildings break the balance of their living environment.

B.Land for them to live on is limited and they are hunted in large numbers.

C.Yellowstone National Park wants to control the number of them.

D.Living closer to humans makes them die from serious diseases.小题2: How many suggestions are made for people to live with bears peacefully?

A.One.

B.Two.

C.Three.

D.Four.小题3: Compared with the early 1800s, the number of grizzly bears has got smaller by ______.

A.exactly 26﹪

B.over 36﹪

C.nearly 64﹪

D.about 96﹪小题4: Which of the following statements is TRUE according to the passage?

A.Grizzly bears are always friendly to the people living in grizzly countries.

B.It is certain that grizzly bears and people can live together peacefully.

C.Grizzly bears are protected only in and around Yellowstone National Park.

D.The grizzly bear is one of the largest meat-eating animals in North America.小题5: What does the last paragraph mainly tell us?

A.How to protect yourself from grizzly bears.

B.How to get grizzly bears out of your way.

C.How to invite grizzly bears to your party.

D.How to live with grizzly bears peacefully.