The evolution of the first animals may have oxygenated（供氧）Earth's oceans. New research
led by the University of Exeter challenges the long held belief that oxygenation of the atmosphere and oceans was a precondition for the evolution of complex life forms.
The study, published in the journal Nature Geoscience, builds on the recent work of scientists in Denmark who found that sponges（海绵动物）一the first animals to evolve一require only small amounts of oxygen.
Professor Tim Lenton of the University of Exeter, who led the new study, said: "We argue that the evolution of the first animals could have played a key role in the widespread oxygenation of the deep oceans. This in turn may have facilitated the evolution of more complex, mobile animals."
Critical to determining oxygen levels in the deep ocean is the balance of oxygen supply and demand. Demand for oxygen is created by the sinking of dead organic material into the deep ocean. The new study argues that the first animals reduced this supply of organic matter一both directly and indirectly.
Sponges feed by pumping water through their bodies, "digesting" the tiny particles of organic matter, and thus helping oxygenate the shelf seas that they live in. By oxygenating more of the bottom waters, the first animals actually increased the removal of the essential nutrient phosphorus（磷）in the ocean. This in turn reduced the productivity of the whole ocean ecosystem, lowering oxygen demand and thus oxygenating the deep ocean.
A more oxygen-rich ocean created ideal conditions for more complex mobile animals to evolve, because they have a higher requirement for oxygen. These included the first predatory（肉食的）animals with guts（内脏）that started to eat one another, marking the beginning of the type of food webs we are familiar with today.
Professor Simon Poulton of the University of Leeds, who is a co-author of the study, added: "This study provides a possible mechanism for ocean oxygenation without the requirement for a rise in atmospheric oxygen. It therefore questions whether the long-standing belief that there was a major rise in atmospheric oxygen at this time is correct. We simply don't know the answer to this at present, which is ultimately key to understanding how our planet evolved to its current habitable state. Geochemists need to come up with new ways to explain oxygen levels on the early Earth."The underlined word "facilitated" in Para. 3 is closest in meaning to＿＿．
| A．prevented | B．promoted | C．interrupted | D．witnessed |
From paragraphs 4 to 6, we can infer that＿＿．
| A．phosphorus can keep the productivity of the ocean ecosystem |
| B．complex animals consume the same amount of oxygen as sponges |
| C．the sinking of dead organic material into the deep ocean produces oxygen |
| D．the existence of the first animals marks the beginning of modern food webs |
From the last paragraph, we can learn Pro. Simon Poulton believes that＿＿．
| A．their study gives a new explanation for the high oxygen content in the air |
| B．oxygen increased greatly in the air as the first animals oxygenated the oceans |
| C．their study answers the question of how the earth evolved to the present state |
| D．ocean oxygenation does not necessarily require a rise in atmospheric oxygen |
The main purpose of the passage is to＿＿．
| A．present the view that the first animals played an active role in oxygenating oceans |
| B．introduce two opposite opinions on how the first animals oxygenated oceans |
| C．analyze how atmospheric oxygen stepped up the evolution of oceanic animals |
| D．explain how oceanic oxygen determines the amount of atmospheric oxygen |
This weekly four-day physical activity schedule will get your kids excited about being active.
Tuesday
When the kids get home from school, don’t let them go straight to the TV and get settled in. Encourage them to get moving and get off the couch by giving them a pedometer（计步器）. Pedometers are the most fun when parents also use one because that turns stepping, walking and running into a game to see who can get the most steps.
Thursday
The kids have done a great job so far this week, but now they are aching for a little more TV time. Instead of turning on cartoons, let them watch fitness movies made just for kids. These movies encourage watchers to get up and dance along to kid-friendly music.
Saturday
Get the whole family out of the house together and over to a park. Bring lots of sports equipment, pack a healthy picnic and have a family competitive sports day. Kids and adults get into groups and play against each other in tennis, basketball or soccer. After everyone has played hard for a couple of hours, stop for a picnic and then if your family isn’t too tired, go back and play some more.
Sunday
Every child loves to play video games and there is no better time to allow kids to play them than on Sunday when no homework is due. But don’t let them play a game that forces them to sit down for hours. Dance games with a floor mat（垫子）to help kids follow the dance moves are popular to kids.
56. What’s the best title for this passage?
A. How to make children like activities.
B. A weekly four-day physical activity plan for kids.
C. Physical activities are important to kids.
D. A plan that will do much good to kids.
57. Parents are advised to use a pedometer together with their kids because ______.
A. they can give their kids some advice about walking
B. it can prevent them from watching TV too much
C. this will allow them and their kids to have a fun competition
D. their kids will not use it if they don’t
58. On Thursday when a kid wants to watch TV, his parents should ______.
A. let him watch it for a short time
B. watch cartoons with him
C . take him out for a walk instead
D. show fitness movies to him
59. The author advises a family to have a meal on Saturday _______.
A. in a park B. in a mountain C. in a restaurant D. at home
The invention of the electric telegraph gave birth to the communications industry. Although Samuel B. Morse succeeded in making the invention useful in 1837, it was not until 1843 that the first important telegraph line was constructed. By 1860 more than 50,000 miles of lines connected people east of the Rockies. The following year, San Francisco was added to the network.
The national telegraph network strengthened the ties between East and West and contributed to the rapid expansion of the railroads by providing an efficient means to monitor schedules and routes. Furthermore, the extension of the telegraph, combined with the invention of the steam-driven rotary printing press by Richard
M. Hoe in 1846, revolutionized the world of journalism. Where the business of news gathering had been dependent upon the mail and on hand-operated presses, the telegraph expanded the amount of information a newspaper could supply and allowed for more timely reporting. The creating of the Associated Press as a central wire service in 1846 marked the arrival of a new era (纪元) in journalism.
71. The main topic of the passage is .
A. the history of journalism B. the origin of the national telegraph
C. how the telegraph network contributed to the expansion of railroads
D. the contributions and development of the telegraph network
72. The word "gathering" in line 11 refers to .
A. people B. information
C. objects D. substances
73. The author's main purpose in this passage is to .
A. compare the invention of the telegraph with the invention of the steam-driven rotary press
B. propose new ways to develop the communications industry
C. show how the electric telegraph affected the communications industry
D. criticize Samuel B. Morse
74. This passage would most likely be found in a .
A. U.S. history book B. book on trains
C. science textbook D. computer magazine
75. It can be inferred from the passage that .
A. Samuel Morse did not make a significant contribution to the communications industry
B. Morse's invention did not immediately achieve its full potential (潜力)
C. the extension of the telegraph was more important than its invention
D. journalists have the Associated Press to thank for the birth of the communications industry
The United States covers a large part of the North American continent. Its neighbors are Canada to the north and Mexico to the south. Although the United States is a big country, it is not the largest in the world. In 1964, its population was over 185,000,000.
When this land first became a nation, after winning its independence (独立) from England, it had thirteen states. Each of the states was represented(代表) on the American flag by a star. All these states were in the eastern part of the continent. As the nation grew toward the west, new states were added and new stars appeared on the flag. For a long time, there were 48 stars. In 1959, however, two more stars were added to the flag, representing the new states of Alaska and Hawaii.
Indians were the first people of the land which is now the United States. There are still
many thousands of Indians now living in all parts of the country. Sometimes it is said that the Indians are "the only real Americans". Most Americans come from all over the world. Those who came first in greatest numbers to make their homes on the eastern coast of North America were mostly from England. It is for that reason that the language of the United States is English and that its culture and customs are more like those of England than those of any other country in the world.
68. The United States didn't have______ states until _____.
A. thirteen; 1959 B. fifty; 1959
C. fifty; this land first became a nation D. fifty;1964
69. Why is English the language of America?
A. English is the Indian's native language.
B. Most Americans come from all over the world.
C. Most of the people who first settled in America were from England
D. Canada is America's nearest neighbor.
70. Which of the following is the best title for the passage?
A. The States of America B. The Language of America
C. The United States of America D. The Culture and Customs of America
Everybody has one of those days when everything goes wrong. This is what happened to Harry.
He got up one morning very late because he had forgotten to wind up（旋） his alarm clock(闹钟). He tried to shave(刮脸) quickly and cut himself. When he got dressed he got blood all over his clean shirt, so he had to find another one. The only other shirt that was clean needed ironing (熨), so he ironed it. While he was ironing it, there was a knock at the door. It was the man to read the electricity meter(表). He showed him where the meter was, said good-bye and found that the iron had burnt a hole in his shirt. So he had to wear the one with the blood on it after all. By this time it was very late, so he decided he couldn't go to work by bus. He telephoned for a taxi to take him to work. The taxi arrived and Harry got in and began to read the newspaper.
In another part of the town, a man had killed a woman with a knife and was seen to run away in a taxi. When Harry's taxi stopped outside his office, a policeman happened to be standing there. He saw the blood on Harry's shirt, and took him to the police station. He was kept till 3 o'clock in the afternoon before the police were sure that he was not the man they wanted. When he finally arrived at the office at about four, his boss took a look at him and told him to go away and find another job.
64. Put the following sentences into correct order according to the passage.
a. The man who read the electricity meter came.b. Harry ironed his shirt.
c. Harry got blood all over his clean shirt.
d. There was a knock at the door.
e. Harry wore the shirt with blood on it.
A. a, b, c, d, e B. b, a, d, c, e
C. b, a, c, d, e D. c, b, d, a, e
65. Why did Harry wear the shirt with blood on it ?
A. He had only one shirt.B. The only other needed ironing.
C. The iron had burnt a hole in his clean shirt.
D. He cut himself and got blood all over his shirt.
66. Harry was taken to the police station because_______.
A. his taxi stopped outside his office and a policeman happened to be there
B. there was blood on his shirt and he was in a taxi
C. a man killed a woman with a knife
D. the murderer(杀人犯) was seen to run away in a taxi
67. His boss told him to go away and find another job because_______.
A. he had been kept by the police B. there was blood on his shirt
C. he was late for work D. he had killed a woman
Will it matter if you don't take your breakfast? Recently a test was given in the United States. Those tested included people of different ages, from 12 to 83. During the experiment, these people were given all kinds of breakfasts, and sometimes they got no breakfast at all. Special tests were set up to see how well their bodies worked when they had eaten a certain kind of breakfast. The results show that if a person eats a proper breakfast, he or she will work with better effect than if he or she has no breakfast. This fact appears to be especially true if a person works with his brains. If a student eats fruit, eggs, bread and milk before going to school, he will learn more quickly and listen with more attention to class.
Opposite to what many people believe, if you don't eat breakfast, you will not lose weight. This is because people become so hungry at noon that they eat too much for lunch, and end up gaining weight instead of losing. You will probably lose more weight if you reduce your other meals.
60. During the test, those who were tested were given ________.
A. no breakfast at all B. very rich breakfast
C. little food for breakfast D. different breakfast or none
61. The results of the test show that ________.
A. breakfast has great effect on work and studies
B. breakfast has little to do with a person s work
C. a person will work better if he has a simple breakfast
D. those working with brains should have much for breakfast
62. The passage mentions that many people believe that if you don't eat breakfast, you will _________.
A. lose weight B. not lose weight
C. be healthierD. gain a lot of weight
63. According to the passage, if a student does not eat breakfast, ___________.
A. he will fall ill B. he will fail to listen to his teacher
C. he will not make progress in his study D. his mind will work more slowly