Trees are useful to man in three very important ways: they provide him with wood and other products;they give him shade;and they help to prevent drought and floods.
Unfortunately, in many parts of the world, man has not realized that the third of these services is the most important. In his eagerness to draw quick profit from the trees, he has cut them down in large numbers, only to find that without them he has lost the best friends he had.
Two thousand years ago, a rich and powerful country cut down its trees to build warships, with which to gain itself an empire. It gained the empire but, without its trees, its soil became hard and poor. When the empire fell to pieces, the country found itself faced by floods and starvation.
Even though a government realizes the importance of a plentiful supply of trees, it is difficult for it to persuade the villager to see this. The villager wants wood to cook his food with, and he can earn money by making charcoal(木炭) or selling wood to the townsman(城市居民). He is usually too lazy or too careless to plant and look after trees. So unless the government has a good system of control, or can educate the people, the forests will slowly disappear.
This does not only mean that the villager’s sons and grandsons have fewer trees. The results are even more serious. For where there are trees their roots break the soil up—allowing the rain to sink in and also hold the soil, thus preventing it being washed away easily, but where there are no trees, the soil becomes hard and poor. The rain falls on hard ground and flows away on the surface, causing floods and carrying away with it the rich topsoil, in which crops grow so well. When all the topsoil is gone, nothing remains but a worthless desert.The purpose that the writer wrote this article is to _________.
A.tell people the use of wood |
B.tell people the function of tree roots |
C.warn that man mustn’t destroy forests any more |
D.explain how trees help man live a better life. |
In the writer’s opinion, _________, or the forests will slowly disappear.
A.measures must be taken |
B.people shouldn’t draw benefit from the tree |
C.government must realize the serious results |
D.unless no trees are cut down. |
According to the article we know it is ________ to prevent the forests from slowly disappearing.
A.necessary but impossible | B.necessary but difficult |
C.impossible and unimportant | D.difficult and impossible |
In the last two paragraphs the writer wanted to make it clear that _________.
A.where there are no trees, the soil becomes poor but soft |
B.where there are many trees, there are more floods |
C.where there are no trees, the land might become desert slowly |
D.floods will make the land become desert |
When, after a year of being alone on his island, Robinson Crusoe sees a footprint in the sand, the reader of Robinson Crusoe trembles. Will Crusoe find another human being to end his loneliness? Is the footprint the sign of an enemy? Since 1719, when Daniel Defoe wrote Robinson Crusoe, thousands of people who enjoy English novels have thrilled to this great adventure story. But few know how the story came to be written. Robinson Crusoe was the first English novel. Its birth brought together the misadventures of a Scotch “failure” and the untapped imagination of an aging English scribbler.
Near the end of the Seventeenth Century, the hot-tempered Alexander Selkirk was charged with bad conduct while in church. Rather than face this charge, he ran away to sea. Several years later, Selkirk found himself on the ship of an English privateer. The privateer was preying on Spanish shipping. But Selkirk quarreled bitterly with the Captain. So, when the ship came to the island of Juan Femandez in the South Seas, Selkirk asked to be put ashore. When he saw that there were no people on the island, he begged to be taken back on board. But the Captain refused—Selkirk had gone too far. Over four years later, Selkirk was rescued by another ship.
When Selkirk got back to England, the story of his life on the island fired the imagination of Daniel Defoe. Defoe had been earning a living by his pen since he was thirty. He was amazingly hard-working. He wrote a whole newspaper three times a week. He also made part of his living from politics. He supported both political parties. He told each party that it had his sole support.Alexander Selkirk spent four years on a desert island because .
A.he sought adventure |
B.he was hot-tempered |
C.he was afraid to face charges |
D.his ship was wrecked |
Daniel Defoe .
A.made his living as a writer |
B.got his start as a writer with the writing of Robinson Crusoe |
C.was very “straight”-he was hardworking and honest |
D.had little power of imagination, but succeeded with his novel because he worked hard |
This passage is mainly about .
A.how Alexander Selkirk was able to survive on the island. |
B.why people enjoy English novels |
C.what the footprint in the sand meant |
D.how Robinson Crusoe came to be written |
According to this passage , which of the following statements is not true?
A.Robinson Crusoe was a successful novel. |
B.Even if Alexander Selkirk had not lived on the island of Juan Femande, Robinson Crusoe would still have been written. |
C.Daniel Defoe lived partly by hard work and partly by his “ wits ”. |
D.With the writing of Robinson Crusoe , the English novel was born. |
The author’s attitude towards Daniel Defoe is .
A.critical | B.supporting | C.both A and B | D.opposing |
I’m afraid to grow old—we’re all afraid. In fact, the fear of growing old is so great that every aged person is an insult and a threat to the society. They remind us of our own death, that our body won’t always remain smooth and responsive, but will someday betray(背叛) us by aging. The ideal way to age would be to grow slowly invisible, gradually disappearing, without causing worry or discomfort to the young. In some ways that does happen. Sitting in a small park across from a nursing home one day, I noticed that the young mothers and their children gathered on one side, and the old people from the home on the other.
Whenever a youngster would run over to the “wrong” side, chasing a ball or just trying to cover all the available space, the old people would lean forward and smile. But before any communication could be established, the mother would come over, murmuring embarrassed apologies, and take her child back to the “young” side.
Now, it seemed to me that the children didn’t feel any particular fear and the old people didn’t seem to be threatened by the children. The division of space was drawn by the mothers. And the mothers never looked at the old people who lined the other side of the park. These well-dressed young women had a way of sliding their eyes over, around, through the old people; they never looked at them directly. The old people may as well have been invisible; they offended the aesthetic eye of the mothers.
My early experiences were somewhat different; since I grew up in a small town, my children had more of a nineteenth-century flavor. I knew a lot of old people, and considered some of them friends.People are afraid of growing old because it is usually associated with ______.
A.insult | B.threat | C.death | D.betrayal |
In the author’s opinion, it is a perfect way to ______.
A.grow old slowly and then die unnoticed |
B.grow old suddenly and then die |
C.shut oneself up from others when growing old |
D.remain young all one’s life and then die suddenly |
It can be inferred that young mothers would try to keep their children away from the old because ______.
A.they feared their children might hurt the old |
B.they didn’t like their children to take up the space belonging to the old |
C.they felt it was wrong to play balls near where the old stayed |
D.they didn’t want their children to have anything to do with the old |
The author believes the division between the old and the young is _____.
A.made by people | B.understandable |
C.formed naturally | D.traditional |
From the passage, we learn that the author ______.
A.used to have the same experience as the young have today |
B.has never been afraid of getting old |
C.was quite free to know and befriend old people in his childhood |
D.both B and C |
Inland waters may be grouped into two general classes: standing waters and flowing waters. As is often the case, the boundary between these two classes is not sharp and clear. A pond is an example of standing water. But most ponds are fed by springs or brooks and most have an outlet. Thus some current of changing water flows through them. On the other hand, a river is an example of flowing water. In some places, however, a river may have such a slow current that it is very difficult to detect.
Standing inland waters differ in size, in age, and in many abiotic environmental characteristics. They range in size from roadside puddles to the Caspian Sea. Puddles may last for only a few days or weeks; ponds, for a few hundred to a thousand years. In general, lakes are older, though the waters of some tropical “lakes” disappear completely during each dry season. Standing waters vary from very shallow to very deep, from clear to muddy, from fresh to salty.
In flowing waters we roughly distinguish between brooks, creeks, and rivers. The size and age of flowing waters are unimportant. Speed of flow, clearness, oxygen content, and other chemical characteristics are used by scientists in studying flowing-water ecosystems.According to the passage, which of the following characteristics of flowing waters is unimportant?
A.Clarity. | B.Size. | C.Speed of flow. | D.Oxygen content. |
The word “abiotic” in paragraph 2 can best be replaced by ______.
A.nonliving | B.living | C.coastal | D.inland |
Which of the following statements is true?
A.Usually the water in a river flows into a pond. |
B.Scientists only study flowing-water ecosystems. |
C.Usually ponds last much longer than puddles. |
D.The Caspian Sea is considered as an example of flowing water. |
From this passage we may know that the distinction between standing waters and flowing waters ______.
A.depends on how people name the waters |
B.is clear |
C.depends on the seasons |
D.is hard to make |
This passage mainly tells us that ______.
A.there are two major classes of inland waters |
B.lakes and rivers are flowing waters |
C.age and size of flowing waters are important |
D.ponds and brooks are standing waters |
During the 1800s, African Americans worked long days in the fields of the American South.To ease their labor, they sang "field hollers" that they had brought from Africa.One person sang a line.Then a group of workers repeated it.The songs' words told of the hardships that people suffered.African Americans sang "shout spirituals", or joyous religious songs.They clapped their hands and stomped their feet to the music.
After the Civil War, the music changed dramatically.African American music, from ballads to church music, took new forms.It also adapted dance music, called "jump-ups".which had great rhythm. Banjos became popular.A blues singer usually played a call and response with the banjo.By the early 1900s, the guitar had replaced the banjo as the main blues instrument.
Northern Mississippi - called the Delta - was the center of the blues tradition.By the 1920s, the Delta had many clubs, so-called juke joints.African Americans listened and danced to music in these clubs.Some of the greatest blues men and women performed there.
Blues have a soulful sound that is easy to recognize.The musical notes are often "bent".That is, they are changed slightly to give a song more strength.Whatever their origin, these bent notes most often define the blues.
Lyrics are the words of a song.Blues lyrics describe everyday life.The lyrics, often about relationships between men and women, are often very intense and personal.They tell about sorrow and overwork.They tell about finding or losing love, having money or being broke, being happy or sad and lonely.The lyrics may use humor to describe life's trials and joys.They almost always use the rhythms of everyday speech.A typical blues stanza, or group of lyrics, has three lines.The second line repeats the first line.The third line has different words.
By the 1940s, large numbers of African Americans had left the Delta and moved north to work. Many settled in Chicago.There, a new kind of "electric", or "Chicago" blues began.Many of its themes were the same, but these blues had "wailing" electric guitars and harmonicas.The music had a steady, strong drumbeat.The loud, driving Chicago blues was excellent dance music.Chicago blues led to the birth of a new music style-rock and roll.The "field holler" is a kind of music that came from ___.
A.the American South. | B.Africa. |
C.Chicago. | D.Asia. |
"Shout spirituals" and "field hollers" are similar in that both_____.
A.used banjos. | B.were sung in church. |
C.included call and response singing. | D.expressed sadness. |
A typical blues Stanza is made up of____.
A.three lines. | B.a harmonica. |
C.a driving beat. | D.four lines. |
One can conclude from the passage that the blues ___.
A.would have widespread without the juke joints of the Mississippi. |
B.served as a form of communication and self-expression. |
C.was successful only in the American South. |
D.there were only greatest blues man performed in these clubs. |
African Americans probably moved to Chicago because ____.
A.the South was too hot in summer. |
B.they liked the Chicago blues. |
C.there were more jobs there. |
D.they wanted to create a new music style. |
Cloud seeding is a method of artificially causing clouds to produce precipitation (降水) in the form of rain or snow.Cloud seeding has also been used in attempts to modify the severity of hail storms and hurricanes.The effectiveness of cloud seeding remains controversial (有争议的).but it continues to be used in some regions to try to increase rainfall for agriculture and to build snow packs for water supplies and power production.
Cloud seeding was developed by American scientists Irving Langmuir and Vincent Joseph Schaefer during and after World War II.Their work began as an effort to learn more about the buildup of ice on airplane wings, and eventually led them to attempt to create rainfall by releasing several pounds of crushed frozen carbon dioxide into a cloud from an airplane.In this form, the carbon dioxide is called dry ice.On November 13, 1946, the technique appeared to produce snow directly under the cloud; the snow then turned to rain as it fell to the ground.
For their experiment, Langmuir and Schaefer selected a supercooled cloud, one in which the water droplets remain liquid in subfreezing temperatures.Their theory was that small grains of dry ice falling through the cloud would cause tiny droplets of water vapor in the cloud to freeze into crystals that attracted more water vapor.Their theory proved to be correct and eventually the crystals became heavy enough to fall from the cloud as snow.As the snow reached the warmer temperatures closer to the ground, it melted and became rain.
Another scientist, Bernard Vonnegut, produced a method of cloud seeding using silver iodide (碘化银).He used particles of silver iodide because its crystal structure resembled that of ice in clouds.Silver
iodide also had practical advantages over frozen carbon dioxide It could be stored at room temperature
and did not require an airplane as a delivery mechanism.Instead, silver iodide crystals could be fired by
cannons (大炮) high into the air, where wind carried them into the clouds.According to the text, Langmuir and Schaefer had intended to deal with__
A.how to freeze carbon dioxide
B.how to remove ice on plane wings
C.how to make weather forecast for the war
D how to hide planes in clouds at warWhat is the CORRECT order of the course for cloud seeding with dry ice?
a.snow becoming rain in wanner temperatures b.crystals attracting more water vapor
c.crystals falling in the form of snow d.crystals becoming very heavy
e.freezing tiny droplets of water vapor into crystals
f.putting small grains of dry ice in the cloud
A.a-c-f-d-b-e | B.b-f-e-a-c-d |
C.f-e-b-d-c-a | D.e-a-d-c-b-f |
Bernard chose silver iodide as a method of cloud seeding because___.
A.it is much cheaper than dry ice | B.it can be stored at any rooms |
C.it can be sent into clouds by wind | D.it is similar |
The best title for the passage may be "____".
A.Cloud Seeding |
B.Artificial Raining |
C.Weather Changing |
D.Cloud Gathering |
How many methods of cloud seeding are mentioned in the passage?
A.three | B.two | C.one | D.four |