Many scientists have been probing psychological problems.A．solvingB．exploringC．settlingD．h

als and plants in the last two years.

A) is; have B) is; has C) are; have D) is; are

A. unlikely

B. unfriendly

C. forbidden

D. vulnerable

r work _____.

(A) remain a theory to be further proved (C) have been challenged by many other experts

(B) have been generally accepted (D) are practiced by the researchers themselves

_ today and are being modified by the work of scientists of our time.

A) are to challenge B) may be challenged

C) have been challenged D) are challenging

understanding of how many stars there are in the galaxy than how many species there are on Earth？ Their estimates of global species diversity vary from 2 to 100 million species. Most people agree on an estimate of somewhere near 10 million and yet only 1.75 million have actually been named. Current knowledge of species diversity is limited. This problem becomes more serious because there is a lack of a central database or list of the world’s species.

New species are still being discovered — even new birds and mammals(哺乳动物). On average, about three new species of birds are found each year, and since 1990, 10 new species of monkeys have been discovered. Other groups are still far from being completely described: an estimated 40 percent of freshwater fishes in South America have not yet been classified.

Scientists were startled in 1980 by the discovery of a huge diversity of insects in tropical forests. In one study of just 19 trees in Panama, 960 new species of beetles were discovered.

As scientists begin investigating other little-known ecosystem, like the soil and the deep sea, “surprising” discoveries of species become commonplace. There is nothing strange about this, though, since as many as a million undescribed species are believed to live in the deep sea. And one gram of a small-sized piece of land might hold 90 million bacteria(菌类) and other microbes(微生物). How many species these communities contain is still anyone’s guess.

16. Which of the following is true？

A) Scientists have a sound knowledge about the diversity of species

B) Scientists don’t know much about the number of stars in the galaxy

C) Scientists show more interest in stars in the galaxy than in species on Earth

D) Scientists don’t agree on the number of species in the world

17. How many species are there on Earth according to most scientists？

A) About 2 million

B) About 10 million

C) About 100 million

D) About 1.75 million

18. In which of the following groups is the discovery of new species not mentioned in

the passage？

A) Birds

B) Monkeys

C) Trees

D) Freshwater fish

19. What can you learn from the passage？

A) The soil and the deep sea belong to communities that haven’t been fully explored

B) It is surprising news wherever new species are discovered in the deep sea

C) About 90 million species are believed to live in the deep sea

D) A million species in the deep sea have been discovered and named

20. Which of the following best reveals the main idea of the passage？

A) Surprising discoveries of new species are commonplace

B) The mystery of the deep sea and the soil remains to be uncovered

C) Knowledge of global species diversity is still limited

D) Estimates of global species diversity vary among scientists

reluctant to engage in a debate with advocates of intelligent design because to do so would legitimize the claim that there’s a meaningful debate about evolution. 译文：许多科学家不愿卷入与“智慧设计论”者的辩论，因为这样做会让如下说法披上合理的外衣：关于进化论的争论是有意义的。()

Many Native Americans closely resemble Asians. This has led most scientists to(1)believe something about Native Americans. They think that most Native Americans(2)from a distant group of people. These people(3)from Siberia across the Bering Strait, between 17,000-11,000 years ago. The exact time and 4 is still under question. That is, it is still a(n)(5)of debate. The time they traveled and the route they took is still being argued, as is whether it happened(6).

(7)recently, some anthropologists (人类学家) argued that the migration occurred 12,000 years ago. However, there are a number of difficulties with this theory —(8)particular, the presence of people in the Americas earlier than one might think. There is growing evidence of human(9)in Brazil and Chile 11,500 years ago or earlier. There is also(10)of humans living in the Americas some 50,000 years ago.(11), other possibilities have been suggested.

They may have(12)the land bridge several thousand years earlier or they may have sailed along the western coast. However, some(13)this theory. They think that humans(14)skills for sailing during that era.

Some consider the genetic and cultural evidence for an Asian origin overwhelming. It should be noted,(15), that some other people are very upset at this idea. Many present-day Native Americans(16)the above theories. They say those who put forward such theories have political(17)They have their own traditional stories that offer(18)of where they came from. Their own stories claim that their(19)are different from what scientists say. Those accounts, though, have mostly been(20)by scholars. Therefore, the origin of Americans still remains a mystery to be explored.

s people today act younger than their parents did at the same age.

Scientists have defined a new age concept and believe it could explain why populations are aging, but at the same time seem to be getting younger.

Instead of measuring aging by how long people have lived, the scientists have factored in how many more years people can probably still look forward to.

"Using that measure, the average person can get younger in the sense that he or she can have even more years to live as time goes on," said Warren Sanderson of the University of New York in Stony Brook.

He and Sergei Scherbov of the Vienna lnstitute of Demography (人口统计学) at the Austrian (奥地利的) Academy of Sciences, have used their method to estimate how the proportion of elderly people in Germany, Japan and the United States will change in the future.

The average German was 39.9 years old in 2000 and could plan to live for another 39.2 years, according to research reported in the journal Nature on Wednesday.

However, by 2050 the average German will be 51.9 years old and will be expected to live another 37.1 years. So middle age in 2050 would occur at around 52 years instead of 40 years as in 2000.

"As people have more and more years to live they have to save more and plan more and they effectively are behaving as if they were younger," said Sanderson.

Five years ago, the average American was 35.3 years old and could plan for 43.5 more years of life. By 2050, the researchers estimate it will increase to 41.7 years and 45.8 future years.

"A lot of our ski/Is, our education, our savings and the way we dear with our health care depend a great deal on how many years we have to live," said Sanderson.

This dimension of how many years people have to live has been completely ignored in the discussion of aging so far.

第36题：People 40 years of age today seem to be as young as

A．their parents were at the same age.

B．their parents were at the age of 30.

C．their children will be at the same age.

D．their children will be at the age of 30.

ivate fertility clinics. Antinori is already f______ for previous controversies such as helping grandmothers to have babies. Yet this time he is not alone in p______ the idea of human cloning. US scientists are working with him on this project, and a r______ group -- the Raelians -- have also announced their intention to offer the service. Of course, with so many couples d______ for a child yet unable to conceive through traditional IVF treatments, there is no s______ of volunteers. It would probably not work trying to prevent cloning, thus some form of regulation is almost i______. At the moment, cloning techniques are far from p______ and most attempts to clone animals end up in f______.

e great discoveries and have done exciting things. They have walked in space, visited the moon, and lived in space laboratories for long periods of time. Some scientists are now working on ways to make it possible for people to live on other planets. They are trying to solve problems of living in space, even though they don’t yet know what all of the problems will be. For example, they don’t’ yet know what problems people would have if they loved being weightless for several years.

If you were a space traveler you might have to spend several months, or even years, in a spaceship. While you were in the ship you wouldn’t live as you usually do. You might have to find new ways to spend your time. Your body would have to adjust to different conditions. And you would have some problems that you never think about here on earth. For example, you would have to have a huge supply of food with you because you can’t go to the supermarket when you’re halfway to another planet. You also would need fresh water and a way to get rid of waste. In fact, there would be many problems to solve in order to live in space.

1. This passage tells us that__________.

A. if you were a space traveler, you had to live in space for some time

B. scientists are trying to solve problems of living in space

C. while you were in the ship you wouldn’t live as you usually do

D. scientists are finding ways to make people live on other planets

2. The sentence “what problems people would have if they loved being weightless” (Para. 1) is probably closest in meaning to ________.

A. people who were light had many problems

B. many problems people would face in space

C. many people who loved to be very light

D. weightless people who loved to have problems

3. The phrase “a huge supple of food” (Para.2) means ________.

A. a huge piece of food

B. the food that is largely supplied on the market

C. a large amount of food

D. the food at the supermarket

4. While you were in the spaceship, you would NOT _______.

A. need fresh water and a way to get rid of waste

B. have some unusual problems

C. go to the supermarket when you were halfway to another planet

D. find new ways to spend your time

5. It can be concluded from the passage that _________.

A. life in space was interesting and exciting

B. if you were a space traveler, you had to stay in space

C. there would be many problems if you wanted to live in space

D. it was easy to enjoy oneself in space