A black hole is a place in space where gravity pulls so much that even light cannot get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying.
Because no light can get out, people can’t see black holes. Space telescopes with special tools can help find black holes. The special tools can see how stars that are very close to black holes act differently from other ones.
Black holes can be big or small. Scientists think the smallest black holes are as small as just one atom. These black holes are very tiny but have the mass of a large mountain. Mass is the amount of matter, or “staff”, in an object.
Another kind of black hole is called “stellar”(星球黑洞). Its mass can be up to 20 times more than the mass of the sun. There may be many stellar mass black holes in Earth’s galaxy. Earth’s galaxy is called the Milky Way.
The largest black holes are called “supermassive”(超大质量黑洞). These black holes have masses that are more than one million suns together. Scientists have found proof that every large galaxy contains a supermassive black hole at its center. The supermassive black hole at the center of the Milky Way galaxy has a mass equal to about four million suns and would fit inside a very large ball that could hold a few million Earths.
Scientists think the smallest black holes formed when the universe began. Stellar black holes are made when the center of a very big star falls in upon itself, or falls apart. When this happens, it exploded part of the star into space. Scientists think supermassive black holes were made at the same time as the galaxy they are in.
A black hole can not be seen because strong gravity pulls all of the light into the middle of the black hole. But scientists can see how the strong gravity affects the stars and gas around the black hole. Scientists can study stars to find out if they are flying around, or orbiting a black hole.
When a black hole and a star are close together, high-energy light is made. This kind of light cannot be seen with human eyes. Scientists use satellites and telescopes in space to see the high-energy light.The gravity of a black hole may become so strong that light cannot get out when ____________.
| A．the star is going to die |
| B．special tools are used on it |
| C．other stars come close to it |
| D．it is seen from the space telescopes |
According to the passage, which of the following is NOT true?
| A．A black hole can be very tiny but extremely heavy. |
| B．The gravity of a black hole holds all light in its center. |
| C．Scientists observe high-energy light through their own eyes. |
| D．Some small black holes came into being as early as the universe. |
Which can be inferred from the passage?
| A．Every galaxy must have a black hole. |
| B．A galaxy is the center of the universe. |
| C．A galaxy consists of a large group of stars and planets. |
| D．Earth’s galaxy is called the Milky Way. |
What does the last sentence in Paragraph 5 suggest?
A. Neither the sun nor the earth is as heavy as a black hole.
B. There is only one supermassive black hole at the center of the Milky Way.
C. The supermassive black hole had existed before the Milky Way was formed.
D. There is a reason why the large black holes are called “supermassive”.
65. The last two paragraph mainly focus on the question of _________.
A. what a black hole is
B. how black holes form
C. how big black holes are
D. how scientists know about black holes
About one million years ago,the Ice Age began.The Ice Age was a long period of time in which four great glaciers(冰川) pushed southward to cover almost all the upper half of North America,and then melted away.Each glacier was a thick sheet of ice and snow that spread out from a center near what is now Hudson Bay in Canada.The winters were long,and the cool summers were too short to melt much of the ice and snow.The evergrowing sheet built up to a thickness of two miles at its center.
As all glaciers do,these great glaciers slid(滑动). They pushed down giant trees in their paths and scraped(刮削)the earth bare(光秃秃)of soil.Many animals moved farther south to escape.Others stayed and were destroyed.
When winters of little snow came,the summer suns into the edges to the ice sheets.As the glaciers melted,rocks,soil and other things that had mixed with the ice and snow were left.New hills,lakes and rivers were formed.
The last of the great glaciers began its melting about 11 000 years ago.Itsmelting formed the Great Lakes.These lakes are today little changed from their early sizes the glaciers.This is the Mississippi Missouri Ohio system.These rivers were miles wide at first.Through the years they settle into their present channels.
The main idea of this passage is ________ .
A.the Ice Age was a long period of time
B.great glaciers covered North America many years ago
C.changes in climate helped to melt the glaciers
D.how glaciers changed North America
2.The author states that all glaciers ________.
A.are two miles thick B.form frozen lakes
C.are a million years old D.move and slide
3.From the information in this passage we know that ________.
A.glaciers are destructive
B.all glaciers in the world move southward
C.the Mississippi Missouri Ohio systems is larger than it was before the Ice Age
D.the Great Lakes are now smaller than they were before the Ice Age
4.The Ice Age lasted almost ____.
A.1 000 years B.100 years C.1 000 000 years D.11 000 years
5.In the last sentence,the word “their” refers to ________ .
A.lakes B.rivers C.glaciers D.systems
The Channel Islands are a group of Britishowned islands lying in the English Channel(海峡) , 10 to 30 miles off the French coast , and 70 to 90 miles from the English coast. There are ten islands with a total land area of 75 square miles and a total population of 123,000. The three largest islands, Jersey, Guernsey, and Alderney, have long been known for the fine breeds(品种) of cattle that are raised on them and named after them.
In earliest known history the islands were considered part of Normandy, whic
h was part of France, but the ruler of Normandy became king of England in 1066, and from then on the islands were looked upon as British land. English control was unbroken until World War Ⅱ,when the Germans held the islands for five years.
Although people on the islands speak both languages and they are considered English, their customs are more French than English.
1.Which of the following maps gives the right position of the Channel Islands?
Br="Britain" Fr="France" Ch="Channel" Islands
2.Jersey,Guernsey, and Alderney breeds of cattle are ________ .
A. considered best in England
B. named after their birthplaces
C. brought to the islands by the Germans
D. raised on wellknown farms by the French
3.The Channel Islands have been continuously under British rule since ___________.
A. earliest known history B. 1066
C. 1930s D. the end of World War Ⅱ
4.Why do people on the Channel Islands follow French way of living?
A. Their islands used to be part of Frence.
B. Their islands are often visited by the French.
C. They came from France.
D. They speak French.
Every year thousands of tourists visit Pompeii, Italy. They see the sights that Pompeii is famous for—its stadium(运动场)and theatres, its shops and restaurants. The tourists do not, however, see Pompeii's people. They do not see them because Pompeii has no people. No one has lived in Pompeii for almost 2 000 years.
Once, Pompeii was a busy city of 22 000 people. It lay at the foot of Mount Vesuvius, a grasscovered volcano(火山). Mount Vesuvius had not erupted(喷发)for centuries, so the people of Pompeii felt safe. But they were not.
In August of AD 79, Mount Vesuvius erupted. The entire top of the mountain exploded, and a huge black cloud rose into the air. Soon stones and hot ash began to fall on Pompeii. When the eruption ended two days later, Pompeii was buried under 20 feet of stones and ashes. Almost all of its people were dead.
For centuries, Pompeii lay buried under stone and ash. Then, in the year 1861, an Italian scientist named Ginseppe began to uncover Pompeii. Slowly,carefully, Ginseppe and his men dug. The city looked almost the same as it had looked in AD 79. There were streets and fountains, houses and shops. There was a stadium with 20 000 seats. Perhaps the most important of all, there were everyday objects, which tell us a great deal about the people who lived in Pompeii. Many glasses and jars had some dark blue colour in the bottom, so we know that the people of Pompeii liked wine. They liked bread too, metal bread pans were in every bakery. In one bakery there were 81 round, flat loaves of bread—a type of bread that is still sold in Italy today.
Tiny boxes filled with a dark, shiny powder tell us that women liked to wear eyemakeup.
Ginseppe has died, but his work continues. One fourth has not been uncovered yet. Scientists are still digging, still making discoveries that draw the tourists to Pompeii.
1.Why do large numbers of people come to Pompeii each year?
A.To visit the volcano.
B.To shop and eat there.
C.To watch sports and plays.
D.To see how Pompeiians lived.
2.Why had so many Pompeiians remained by volcanic Mount Vesuvius?
A.The city nearby offered all kinds of fun.
B.The area produced the finest wine in Italy.
C.Few people expected the volcano to erupt again.
D.The mountain was beautiful and covered with grass.
3.Why did the city uncovered look almost the same as it had looked in AD 79?
A.Because Ginseppe and his men dug it slowly and carefully.
B.Because the city was buried alive and remained untouched.
C.Because scientists successfully rebuilt the city with everyday objects.
D.Because nobody had lived in the city ever since the volcano erupted.
4.What do we know about the Pompeiians who lived 2 000 years ago?
A.They lived more or less the same as Italians now do.
B.They liked women wearing all kinds of makeup.
C.They enjoyed a lazy life with drinking and eating.
D.They went back to Pompeii after the eruption in AD 79.
A new plan for getting children to and from school is being started by a local government in Eastern England. This could end the worries of many parents fear ful for their children's safety on the roads.
Until now the local government have only been prepared to provide bus services for children living more than three miles from their school, or sometimes less if special reasons existed. Now it has been decided that if a group of parents ask for help in organizing transport they will be prepared to go ahead, as long as the arrangement will not lose money and children taking part will be attending their nearest school.
The new plan is to be tried out this term for children living at Milton who attend Impington School. The children live just without the three mile limit and the local government have said in the past that they will not undertake to provide free transport to the school. But now they have agreed to offer a sum of money for a bus service from Milton to Impington and back, a plan which has the support of the school's headmaster.
Between 50 and 60 parents have said they would like their children to take part. Final calculations have still to be carried out, but a government official has said the cost to parents should be less than ￡ 20 a term.
They have been able to arrange the service at a low cost because there is already an agreement with the bus company for a bus to take children who live further away to Impington. The same bus would now just make one more journey to pick up the Milton children. The official said they would get in touch with other groups of parents who in the past had asked if transport could be provided for their children, to see if they would like to take part in the new plan.
1.What is the aim of the plan?
A.To prevent the students' road accident.
B.To relieve the traffic pressure.
C.To save time for the parents and students.
D.To help the parents save money.
2.How can the local government arrange the new bus service at a low cost?
A.By letting the bus run in the morning only.
B.By limiting the number of the students.
C.By obtaining the support from the headmaster.
D.By lining the new bus service with the existing one.
3.The new bus service will be paid for by ________ .
A. the parents B. the local government
C. the bus company D. the local government and the parents
4.Which of the following is possible if the plan is carried out?
A.The bus company will make much more money.
B.The children can choose whatever school they like.
C.The parents can get rid of their worries.
D.The students in Impington School can have free bus rides.
5.This passage is most probably ________ .
A.a personal letter B. a headmaster's report
C.an advertisement D. a newspaper article
The science of physics today is as current as the morning newspaper. Indeed,as
a result of new advances in physics and their rapid application to inventions designed to satisfy man's wants, the world itself has been changing rapidly. Space technology, industrial technology, and the technology of the home, the farm, the office, the bank, and the department store have all been revolutionized.
Clearly, every grownup today would understand the world he lives in much better if he knew something about physics. Whether it be Congress(美国国会) voting huge sums of money for new warships, space exploration, or atomic energy；the office staff learning to use a new computer；son Bobby wanting to know about going to the moon；or the housewife learning to operate a new electric stove physics seems to be everywhere.
Teachers in thousands of schoolrooms in America are trying to communicate some of the excitement and importance of these new developments to their students.
They know that some of their eager students will someday be scientists and will them selves then contribute(贡献) to the development of new knowledge or its application to new things.
But in any case, they can be sure that if they bring a knowledge of science(any science) to their students in meaningful and stimulating ways, they have contributed much to helping each one live a more meaningful life.
1.The application of new advances in physics to inventions ________ .
A.may solve all the problems in teaching
B.can help people understand the meaning of life
C.is intended to meet people's needs
D.makes people understand the voting rules of the Congress
2.According to the passage, many American teachers are making efforts to do all of the following EXCEPT ________.
A.stimulating their students' curiosity in physics
B.making their students understand the importance of physics
C.giving their students the information of new advances in science
D.creating excitement about physical education among their students
3.The word “themselves” in the third paragraph refers to ________ .
A.some of the eager students B.the students in the classroom
C.the teachers giving lessonsD.all the scientists in physics
4.The first two paragraphs of the passage mainly tell us about ________ .
A.new advances in physics B.the use of physics in our life
C.the science of physicsD.modern developments in science