An ExperimentMaterials: Newspaper, ‘ACE’ hardware ruler (1/8 “think”), a flat ta
题型：不详难度：来源：
An Experiment
Materials: Newspaper, ‘ACE’ hardware ruler (1/8 “think”), a flat table.
Purposes: We’ll show that there is air pressure pushing on us, from every direction while we’re on this Earth.
|
less than half of it hanging off the edge of the table
(see the drawing below). Next place a sheet of newspaper
over the ruler flat against the table. Make sure to have
as little air as possible under the paper so that the fold line of the newspaper is at the ruler. Then quickly strike the end of the ruler hanging off the edge of the table. If you strike it quick enough, the ruler will break near the table edge.
What’s going on?
The Earth is covered in a layer of air that is nearly 80 miles thick and at sea level (the bottom) exerts or ‘pushes’ hard almost 15 pounds of pressure per square inch. That means that a full sheet of newspaper laid out flat has nearly 9,300 pounds of air above it.
When you break the ruler above, you are able to break it because of the "heavy" air pushing down on the paper while you quickly strike the ruler. At first the table is pushing back on the paper, and if you move the ruler quick enough, other air around the edges of the paper can"t get under the paper fast enough, so you are trying to lift that 9,300 pounds with the ruler! Some air gets under the paper, but not enough, so the ruler breaks.
1．By doing the experiment, we may realize .
A．that air exits everywhere
B．why there are directions
C．that we live with air pressure
D．how air helps on the earth
2．How many steps are there in this experiment? .
A．2 B．3 C．4 D．5
3．The underlined word “exert” probably means .
A．cover completely B．advocate actively
C．influence gradually D．press heavily
4．The ruler breaks under a quick strike mainly because of .
A．the air pressure on the newspaper B．the heavy weight of the newspaper
C．the heavy weight of the flat table D．the strong power used on the ruler
答案
小题1:C
小题2:B
小题3:D
小题4:A
解析
举一反三
It was Thanksgiving morning and in the crowded kitchen of my small home I was busy preparing the traditional Thanksgiving turkey when the doorbell rang. I opened the front door and saw two small children in rags(破旧衣服) huddling together inside the storm door on the top step.
"Any old papers, lady? " asked one of them.
I was busy. I wanted to say "no" until I looked down at their feet. They were wearing thin little sandals(凉鞋), wet with heavy snow.
“Come in and I"ll make you a cup of hot cocoa.”
They walked over and sat down at the table. Their wet sandals left marks upon the floor. I served them cocoa and bread with jam to fight against the cold outside. Then I went back to the kitchen and started again on my household budget.
The silence in the front room struck me. I looked in. The girl held the empty cup in her hands, looking at it. The boy asked in a flat voice, "Lady, are you rich? "
"Am I rich? no!"
I looked at my shabby slipcovers(旧家具套). The girl put her cup back in its saucer (茶托;浅碟)carefully and said, "Your cups match your saucers." Her voice was hungry with a need that no amount of food could supply. They left after that, holding their bundles of papers against the wind. They hadn"t said "Thank you." They didn"t need to. They had reminded me that I had so much for which to be grateful.
Plain blue china(瓷的) cups and saucers were only worth five pence. But they matched.
I tasted the potatoes and stirred the meat soup. Potatoes and brown meat soup, a roof over our heads, my man with a good steady job--these matched, too.
I moved the chairs back from the fire and cleaned the living room. The muddy prints of small sandals were still wet upon my floor. Let them be for a while, I thought, just in case I should begin to forget how rich I am.
1. Why did the writer let the children in?
A. She showed great pity on them.
B. She wanted to sell old papers.
C. She knew them and wanted to make them a cup of cocoa.
D. She wanted to invite them to her Thanksgiving party.
2. The girl thought the writer was rich perhaps because_________
A. she saw that the lady"s room was comfortable
B. she saw the cups matched the saucers
C. the writer"s slipcovers were very new
D. the woman had expensive clothes
3.What was the weather probably like when the story happened?
A. cloudy B. sunny C. windy D. snowy
4. From the passage, we can infer that whether you are rich depends on_______
A. how much money you have had B. how you feel about your life
C. how you have helped others D. what job you are doing
C
Not many years ago, some American farmers began to complain about hawks(鹰). The hawks were killing chickens. The farmers did not know what to do. They went to the government officials and asked for help.
The officials said, “ We’ll pay you for each hawk you kill.” The farmers began to kill the hawks. Many hawks were killed, but the farmers now had another problem. The field mice were growing in number and they were eating up the farmers’ corn. Hawks eat not only chickens but also field mice. They eat more field mice than chickens. But if the farmers had known that, they would not have upset(打乱) the balance of nature. In one part of the USA, there are deer which eat a kind of wild rose. The deer are eaten by mountain lions. The number of deer, mountain lions, and wild rose does not change much if people stay away from them. If there are too many deer, mountain lions will increase rapidly in number and kill many deer. If there are too many mountain lions, there will be fewer deer and there will be more roses.
It is always necessary for us to keep the balance of nature. The government once killed almost all the mountain lions to protect the deer. Soon there were so many deer that they ate up all the wild roses. Then they began to eat the green leaves of young trees which were important to the farmers.
So the farmers protected their trees from the deer. The deer had nothing to eat, and many of them died.
The government learned a valuable lesson from nature.
44. What had happened after the hawks were killed?
A. People wouldn’t worry about their chickens.
B. The number of the field mice became too large.
C. The number of the field mice became small.
D. The field mice were eating up the farmers’ corn.
45. Why did American people have to protect their trees?
A. Because the mountain lions destroyed the trees.
B. Because there were so many deer that they began to eat the green leaves.
C. Because they wanted the trees to grow well.
D. Because the trees are more important than the deer.
46. What can we learn from the article?
A. We must keep the balance of nature.
B. We must not kill any animals.
C. we must feed the hawks with our corn to keep the balance of nature.
D. Both A and B.
阅读下面短文，从短文后各题所给的四个选项（A、B、C和D）中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。
Red roses were her favorites, her name was also Rose. And every year her husband sent them, tied with pretty bows. The year he died, the roses were still 16 to her door.
Each year he sent her roses, and the 17 would always say, “I love you even more this year, than last year on this day.” My love for you will always 18 , with every passing year. “She knew this was the last time 19 the rose would appear. Her loving husband did not know that he would 20 . he always liked to do things early. Then, if he got too busy, 21 would work out fine.”
A year went by, and it was 22 to live without her mate. Then, the very hour, as on Valentines before, the doorbell rang, and there were roses, sitting by her door. She brought the roses 23 , calling the florist shop. The owner answered, and she asked him , if he would explain, why would someone do this to her, 24 her such pain?
“I know your husband passed away, more than a year ago,” The owner said, “I knew you’d 25 , and you would want to know. “ “ The flowers you received today, were 26 in advance.” “Your husband always planned ahead, he left nothing to chance.”
She thanked him and 27 the phone, her tears now flowing hard. Her fingers shaking, as she slowly reached to 28 the card. Inside the card, she saw that he had written her a note. This is what he wrote: “Hello my love, I know it’s been a year 29 I’ve been gone, I hope it hasn’t been too hard for you to overcome.” “I know it must be lonely, and the pain is very 30 . for if it was the other way, I know how I would feel. The love we shared 31 everything so beautiful in life. I loved you more than words can say.”
“You were my friend and lover, I know it’s only been a year, 32 please try not to grieve. I want you to be happy, 33 when you shed your tears. That is why the roses will be sent to you for years.”
“ When you get these 34 , think of all the 35 that we had together, and how both of us were blessed. I have always loved you and I know I always will. My love, you must go on, you have some living still.”
16. A. passed B. shown C. presented D. delivered
17. A. note B. message C. line D. information
18. A. disappear B. decrease C. grow D. keep
19. A. that B.when C. which D. what
20. A. pass by B. pass away C. pass down D. pass on
21. A. everything B. something C. nothing D. anything
22. A. happy B. meaningful C. hard D. impossible
23. A. in B. out C. along D. up
24. A. curing B. healing C.causing D. killing
25. A. ask B. wonder C. doubt D. telephone
26. A. booked B. grown C. planted D. designed
27. A. picked up B. turned up C.held up D. hung up
28. A. buy B. get C.read D. write
29. A. when B. that C. before D. since
30. strong B. weak C. true D. real
31. A made B. bad C. let D. left
32. A. so B. but C. though D. still
33. A. even B. only C. merely D. just
34. A. roses B. belongings C. congratulations D. remarks
35. A. sadness B. disappointment C. happiness D. sufferings
第二部分：语言知识及运用 第一节完形填空 (共10小题；每小题2分，满分20分)
As waiters, we deal with customers every day and when something goes wrong, somehow we have the ability to keep on going．It’s our responsibility to 16 the customer．
I remember my first waiter job was at a fine restaurant. One afternoon，the manager informed all the cooks and waiters that a VIP group were coming for lunch. The group were 17 VIPs in the city’s fashion industry．
After the group arrived and got 18 comfortably, drinks were ordered. Normally, the head waiter would be in charge of wine service. However, the manager asked me to serve that afternoon. I had never done wine service, nor had l ever served a group of twelve．
I arranged 12 wine glasses on the tray and went to the table. As I set one of the glasses in front of the first customer, somehow I had 19 my grip and six glasses fell on top of a young woman, and then to the floor and lay in pieces. I felt frightened and my face turned red. I apologized many times to the woman and to the rest of the group．
Quickly, the manager 20 my aid and helped in the clean-up and sent out their drinks right away. I didn’t understand why, but the group were forgiving me and the young woman 21 informed me it was OK.
My manager pulled me to the side and said, “If you know why an accident happened, learn from it and move on. You still have a table to serve and you can’t show your 22 or your disappointment. Mistakes and accidents do happen. Keep your 23 up and be confident. The glasses are replaceable.”
I understood why he was truly a well-respected restaurant manager within the neighborhood. His 24 relationship with the group made the situation 25 and the group forgave me for that．
16．A. welcome B. feed C. invite D. please
17．A. let in as B. made up of C. added up to D. recognized as
18．A. introduced B. satisfied C. seated D. dressed
19．A. got B. caught C. forgot D. lost
20．A. took over B. came to C. gave up D. rushed against
21．A. repeatedly B. regretfully C. impatiently D. angrily
22．A. apology B. excitement C. nervousness D. carelessness
23．A. nose B. face C. head D. hand
24．A. new B. famous C. terrible D. close
25．A. calm B. comfortable C. special D. possible
One way to avoid accidents is better driving . Another is better roads and bridges . Engineers in the Unites States have designed ten new concrete mixtures that they think could make bridges last longer .
Professor Paul Tikalsky leads the experiments by a team at Pennsylvania State University . He says bridges made of concrete now last about twenty-five to thirty-five years . But he says the new mixtures might extend that to seventy –five or even one-hundred years .
Concrete is made of stone , sand , water and cement(水泥). The materials in the cement hold the concrete together . Ancient Romans built with concrete . Yet strengthened concrete bridges did not appear until the late 1800s . People keep looking for new ways to improve concrete . Professor Tikalsky says it is one of the most complex of all chemical systems .
The new mixtures designed by his team contain industrial waste products . He says these make the concrete better able to resist damage from water and salt over time . One of the products is fly ash . This is released into the air as pollution when coal is burned .
Professor Tikalsky says particles (颗粒)of fly ash are almost exactly the same size and chemical structure as Portland cement . This is the most costly material in concrete . So using fly ash to replace some of it would save money .
The federal government is paying for part of the research . Engineers anywhere can use the technology . Professor Tikalsky says some of the ideas have already been put to use in China , the Philippines and other countries .
小题1:Why did the United Nations launch the campaign ?
| A．Because the United Nations wanted to reduce road accidents and economic costs |
| B．Because two million people were killed in the accidents . |
| C．Because engineers wanted to design ten new concrete mixtures . |
| D．Because the United Nations made bridges of the new mixtures which could last for about 20 to 35 |
小题2:What does the underlined word “ this ” in the sixth paragraph refer to ?
| A．Fly ash | B．Portland cement | C．Sand | D．Chemical |
| A．Ten new concrete bridges have already been built in the United States . |
| B．A new concrete bridge could last 50 more years than an ordinary concrete one . |
| C．People didn’t know how to build with cement until the late 1800s . |
| D．Water and salt won’t do any damage to bridges over time . |
| A．The causes of road accidents . | B．The advantages of fly ash |
| C．The measures of avoiding road accidents | D．Latest information about long-life concrete bridges |
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