We all know the troth that ______ there are air, water and sunlight, there are living thin
A.in wherever
B.that wherever
C.where
D.that
A.in wherever
B.that wherever
C.where
D.that
We all know that______speak louder than words.
A.movements
B.performance
C.operations
D.actions
From what Mr. Collins said, we can know that he_________ .
A.had only an incomplete picture of what happened
B.heard and saw nothing at all
C.talked to the pilot
D.was once a pilot
Perhaps the best way to think of our present situation is to imagine a train coming into a switchyard. All of the switches are set before the train arrives, so that its path is completely determined. Some switches we can see, others we can not. There is no ambiguity if we can see the setting of a switch: we can say with confidence that some possible futures will not materialize and others will. At the unseen switches, however, there is no such certainty. We know the train will take one of the tracks leading out, but we have no idea which one. The unseen switches are the true decision points in the future, and what happens when we arrive at them determines the entire subsequent course of events.
When we think about the future of the universe, we can see our "track" many billions of years into the future, but after that there are decision points to be dealt with and possible fates to consider. The goal of science is to reduce the ambiguity at the decision points and find the true road that will be followed.
According to the passage, it is difficult to be certain about the distant future of the universe because we ______.
A.have too many conflicting theories
B.do not have enough funding to continue our research
C.are not sure how the universe is put together
D.have focused on investigations of the moon and planets
When we think about the future of the universe, we can see our "track" many billions of years into the future, but after that there are decision points to be dealt with and possible fates to consider. The goal of science is to reduce the ambiguity at the decision points and find the true road that will be followed.
According to the passage, it is difficult to be certain about the distant future of the universe because we______.
A.have too many conflicting theories
B.do not have enough funding to continue our research
C.are not sure how the universe is put together
D.have focused our investigations on the moon and planets
People living in different countries made different kinds of words. Today there are about fifteen hundred different languages in the world. Each contains many thousands of words. A very large English dictionary, for example, contains four or five hundred thousand words. But we do not need all these. Only a few thousand words are used in everyday life.
The words you know are called your vocabulary. You should try to make your vocabulary bigger. Read as many books as you can. There are plenty of books written in easy English for you to read. You will enjoy them. When you meet a new word, find it in your dictionary. Your dictionary is your most useful book.
From this passage, we know that ______.
A.man never made sounds
B.man made animal sounds
C.man used to be like animals to make sounds
D.man learned from the animals to make sounds
Recently I have avoided watching games, not even at a TV live coverage, still less to the match in person. That's because I know I couldn't control myself. When watching a match, I'll inevitably take sides and be emotionally involved, strongly wishing for the triumph of the side over its opponent. As I often side with the "weaker" in a match, watching it will only spell worry and misery for me.
Not long ago when I accompanied my wife to a super world tennis match my horizons broadened as regards sports competition. It seemed to me that wins and losses were relative and transient. What mattered was the ever-higher level achieved through contest. Victory was a result of all the efforts made by both sides. As one of the audience, I should applaud the energetic performance of both to the neglect of the result. Why should I regard the contest as a life-and-death struggle, the winner as survival and the loser as dead?
The basketball team was often defeated because ______.
A.the team members didn't know how to play basketball
B.the team members were students who only know how to study book knowledge
C.there were only one or two members who were qualified for basketball
D.the morale of the team was low
A. But Komfeld said scientists will not know about the applicability of the drugs in humans until a similar study is done on humans. “What’s very encouraging is that these drugs were developed to treat humans, and they are well understood, because they’ve been used for a long time, ” he said。
B. Later the scientists discovered that two related anticonvulsant drugs also lengthened the lives of the worms-in the case of one drug, by almost 50 percent. “This was a big surprise to use, Komfeld said. ”“We didn’t think anticonvulsant drugs had any particular relationship to aging. That connection was completely unexpected. ”
C. Roundworms are a poor subject for experiments, because they are not like humans, even though their molecules are similar. For example, they have no bones, nor do they show emotions, making it difficult to know how exactly human subjects would react to these drugs in large quantities. However, using the worms allows experiments to be conducted quickly, because they do not live for long。
D. “Somehow the neural activity seems to regulate the aging of all of the body the skin, musculature, and reproductive tract, ” Kornfeld said. “Somehow the nervous system coordinates the progress of all these tissues, evidently, though the life stages. But we don’t know how it does that. ”
E. The discovery may also shed light on the little-understood aging process. Since the drugs act on the neuromuscular systems of both humans and worms, the findings hint at a link between neural activity and aging。
F. Unlike vertebrates, the worms are ideal subjects for the study of aging because of their short life spans, which last only a couple of weeks in a laboratory. The worm is well known in genetics, and the worm’s genome has been sequenced。
G. Use of this drug has been permitted by law since 1998 and wider use is now expected as a result of the studies. “We can clearly link this drug with human aging, but we still need to find proof, says Kornfeld optimistically. ”
There is no creature that does not need sleep or complete rest every day.
If you want to know why, just try going without sleep for a long period of time. You will discover that your mind and body would become too tired to work properly. You would become irritable and find it hard to think clearly or concentrate on your work. So sleep is quite simply the time when the cells of your body recover from the work of the day and build up supplies of energy for the next period of activity.
One of the things we all know about sleep is that we are unconscious in sleep. We do not know what is going on around us. But that doesn't mean the body stops all activity. The important organs continue to work during sleep, but most of the body functions are slowed down.
For example, our breathing becomes slower and deeper. The heart beats more slowly, and the blood pressure is lower. Our arms and legs become limp(柔软的) and muscles are at rest. It would be impossible for our body to relax to such an extent if we were awake. So sleep does for us what the most quiet rest can not do.
Your body temperature becomes lower when you are asleep, which is the reason people go to sleep under some kind of covers. And even though you are unconscious, many of your reflexes(习惯性思维) still work. For instance, if someone tickles(使觉得痒) your foot, you will put it away in your sleep, or even brush a fly from your forehead. You do these things without knowing it.
If you don't have as much sleep as your body needs, you will ______.
A.work properly
B.think clearly
C.keep your attention on your work
D.easily get angry
A. But Komfeld said scientists will not know about the applicability of the drugs in humans until a similar study is done on humans. “What’s very encouraging is that these drugs were developed to treat humans, and they are well understood, because they’ve been used for a long time, ” he said。
B. Later the scientists discovered that two related anticonvulsant drugs also lengthened the lives of the worms-in the case of one drug, by almost 50 percent. “This was a big surprise to use, Komfeld said. ”“We didn’t think anticonvulsant drugs had any particular relationship to aging. That connection was completely unexpected. ”
C. Roundworms are a poor subject for experiments, because they are not like humans, even though their molecules are similar. For example, they have no bones, nor do they show emotions, making it difficult to know how exactly human subjects would react to these drugs in large quantities. However, using the worms allows experiments to be conducted quickly, because they do not live for long。
D. “Somehow the neural activity seems to regulate the aging of all of the body the skin, musculature, and reproductive tract, ” Kornfeld said. “Somehow the nervous system coordinates the progress of all these tissues, evidently, though the life stages. But we don’t know how it does that. ”
E. The discovery may also shed light on the little-understood aging process. Since the drugs act on the neuromuscular systems of both humans and worms, the findings hint at a link between neural activity and aging。
F. Unlike vertebrates, the worms are ideal subjects for the study of aging because of their short life spans, which last only a couple of weeks in a laboratory. The worm is well known in genetics, and the worm’s genome has been sequenced。
G. Use of this drug has been permitted by law since 1998 and wider use is now expected as a result of the studies. “We can clearly link this drug with human aging, but we still need to find proof, says Kornfeld optimistically. ”
(31)
A.number
B.length
C.depth
D.width
Most of us have also had trips that we would (14) to forget. Many conditions Can produce a bad traveling experience. For example,if the four conditions listed above do not exist,we will probably have a bad experience, (15) at best a difficult (16) . Students who travel to a foreign country to study often have a difficult trip. They usually travel alone. They don't know the language of the new country (17) . They often arrive in the new country (18) a huge international airport. From the airport,they need to find their way to their school. Maybe they need to change airplanes,to take a bus,a train,or a taxi. They need to do all this in a country (19) everything is unfamiliar. Later,after the experiences are over,they Can laugh. But at the (20) ,they feel terrible.
A. include
B. conclude
C. hold
D. contain