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Many scientists are now making a study of animal and plant life in the sea to find n
A)为找到人类的新起源,许多科学家正在研究模拟海洋动植物的生活环境。
B)许多科学家正在海洋里为人类寻找新的动植物资源。
C)为给人类找到新的资源,许多科学家在研究海洋生物的生活。
D)为给人类找到新的资源,许多科学家在研究海洋动植物。
E)许多科学家在研究海洋动植物的过程中为人类找到了新的资源。
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A)为找到人类的新起源,许多科学家正在研究模拟海洋动植物的生活环境。
B)许多科学家正在海洋里为人类寻找新的动植物资源。
C)为给人类找到新的资源,许多科学家在研究海洋生物的生活。
D)为给人类找到新的资源,许多科学家在研究海洋动植物。
E)许多科学家在研究海洋动植物的过程中为人类找到了新的资源。
Scientists say that many factors ______ changes in the weather.
A.bring in
B.bring off
C.bring about
D.bring forward
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.
Many of the scientists and engineers are judged ______how great their achievements are.
A.in spite of
B.in ways of
C.in favor of
D.in terms of
At the beginning, how did many scientists view Peppeberg's work?
A. It would reveal a creature's mind.
B. It would probably end in failure.
C. It would be hard to judge its value.
D. It would be a long-term project.
The main idea of this passage is ______.
A. many animals die during hibernation
B. hibernation protects animals during the wintertime
C. scientists feel puzzled about hibernation
D. some bats hibernate and others do not
We may conclude from the text that .
[A] human cloning will not succeed unless the technique is more efficient
[B] scientists are optimistic about cloning technique
[C] many people are against the idea of human cloning
[D] cloned animals are more favored by owners even if they are weaker
How will scientists do this? People can' t go to the stars. The stars are far away. A person would take hundreds of years to the next star in a spaceship. So scientists are sending out radio signals. These signals travel in space at the speed of light. At that speed, radio signals will take 25 years to reach the next star. The signals ask "Is there anyone out here?". Living things in space must have machines to hear the signals. We will not get an answer to our signals for more than 50 years. However, scientists are already listening. Someone from space may be trying to send signals to us, too.
Scientists also have sent large telescopes into space. A telescope can make things look larger. The telescopes are going around the earth. They are looking for life on other worlds. In the next few years we may get an answer to the question, "Is there life in space.
People always thought about the question, ______.
A.How can scientists use machines to look for a star?
B.How far away are the stars?
C.How many years a person would take to go to the next star in a spaceship?
D.Is there life in space?
1.( );
A.women
B.parents
C.men
D.wives
2.( );
A.to
B.in
C.on
D.of
3.( );
A.young
B.double
C.remarried
D.single
4.( );
A.this
B.that
C.it
D.which
5.( );
A.to tell
B.tell
C.of telling
D.telling
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.
Not long age, experiments showed that birds rely on the sun to guide them during daylight hours. But what about birds that fly by night? Tests with artificial stars have proved that certain night - flying birds are able to follow the stars in their long - distance flights.
A dove (鸽子) had spent its lifetime in a cage and had never flown under a natural sky. Yet it showed an inborn ability to use the stars for guidance. The bird's cage was placed under an artificial star - filled sky. (76) The bird tried to fly in the same direction as that taken by his outdoor cousins. Any change in the position of the artificial stars caused a change in the direction of his flight.
(77) But the stars are apparently their principal means of navigation (航行) only. When the stars are hidden by clouds, they seemingly find their way by such landmarks as mountain ranges, coast lines, and river courses. But when it's too dark to see these, the doves circle helplessly, unable to find their way.
The reason why birds don't get lost on long flights ______.
A.have been known to scientists for many years
B.have only recently been discovered
C.are known by us
D.will probably remain a mystery
"Ah, yes," replied the manager, "but America has treasures that Japan can never hope to possess."
"You mean our mineral wealth and bountiful farms?
"Ah, no. I was referring to Caltech and MIT."
America's scientific institutions--its technological universities and government laboratories--are the en vy of the world , producing ideas, devices and medicines that have made the U.S. prosperous, improved the lives of people around the globe and profoundly affected their perception of the world and the universe. This tremendous creativity is reflected in tile technical reports that are published in scientific journals throughout the world. Fully 35 % of them come from scientists doing their research at American institutions.
Yet American dominance can no longer be taken for granted. Many recent U. S. achievements and a wards stem in large measure from generous research grants of the past, and any weakening of government and industry commitment to support of basic research could in the next few decades cost the nation its scientific leadership. Some slipping is already divalent. In high-energy physics, where Americans once reigned supreme, Western Europe now spends roughly twice as much money as the U. S. Result. the major high-energy physics discoveries of tile past few years have been made not by Americans but by Europeans.
Even so, money alone cannot guarantee scientific supremacy. Freedom of inquiry, an intellectually stimulating environment and continuous recruitment of the best minds must accompany it. That combination has been achieved in many U.S. institutions--educational, governmental and industrial--but perhaps no where more successfully than at the National Institutes of Health, Bell Laboratories and Caltech.
America's technological universities and government laboratories are generally ______.
A.loved by scientists in other parts of the world
B.disliked by scientists in other parts of the world
C.admired by scientists in other parts of the world
D.jealous of scientists in other parts of the world