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Judging from the fact that the other scouts haven't arrived, they__________the bu
Judging from the fact that the other scouts haven't arrived, they__________ the bus.
A. might miss
B. could miss
C. must have missed
D. should have missed
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Judging from the fact that the other scouts haven't arrived, they__________ the bus.
A. might miss
B. could miss
C. must have missed
D. should have missed
Judging from this passage, people of the Middle Ages probably ______.
A. treated black cats with respect
B. treated black cats badly
C. were witches if they had black cats
D. thought black cats were beautiful
Judging from his accent, I can ______ that he is from the south.
A.speak
B.look tell
C.tell
D.show
Asteroids are different forms of the meteoroids that race across the night sky. Most orbits the sun far from Earth and don't threaten us. But there are also thousands of asteroids whose orbits put them on a violent coming course together with Earth.
Buy $ 50 million worth of new telescopes right now. Then spend $10 mil]ion a year for the next 25 years to locate most of the space rocks. By the time we spot a fatal one, the scientists say, we'll have a way to change its course.
Some scientists favor pushing asteroids off course with nuclear weapons. But the cost wouldn't be cheap.
Is it worth it? Two things experts consider when judging any risk are: 1) How likely the event is; and 2) How bad the consequences if the event occurs. Experts think asteroids big enough to destroy lots of life might strike Earth once every 500,000 years. Sounds pretty rare but if one did fall it would be the end of the world. "If we don't take care of these big asteroids, they'll take care of us. "Says one scientist. "Its that simple."
The cure, though, might be worse than the disease, Do we really want fleets of nuclear weapons silting around on Earth? "The world has less to fear from doomsday rocks than from a great nuclear fleet set against them. "Said a New York Times article.
What does the passage say about asteroids and meteoroids?
A.They are heavenly bodies similar in nature.
B.There are more asteroids than meteoroids.
C.They are heavenly bodies different in composition.
D.Asteroids are more mysterious than meteoroids.
When we see well, we do not think about our eyes very often. (79) It is only when we cannot see perfectly that we realize how important our eyes are.
People who are nearsighted can only see things that are very close to their eyes. Everything else seems blurry (模糊的). Many people who do a lot of close work, such as writing, reading and sewing, become nearsighted. Then they have to wear glasses in order to see distant objects clearly.
People who are farsighted suffer from just the opposite problem. They can see things that are far away, but they have difficulty in reading a book unless they hold it at arm's length. If they want to do much reading, they must get glasses, too.
Other people do not see clearly because their eyes are not exactly the right shape. They have what is called astigmatism (散光). This, too, can be corrected by glasses. Some people's eyes become cloudy because of cataracts (白内障). Long ago these people olden became blind. Now, however, it is possible to operate on the cataracts and remove them.
Having two good eyes is important for judging distances. Each eye sees things from a slightly different angle. To prove this to yourself, look at object out of one eye; then look at the same object out of your other eye. You will find the object's relation to the background and other things around it has changed. The difference between these two different eye views helps us to judge how far away an object is. People who have only one eye cannot judge distance as people with two eyes.
We should take good care of our eyes ______.
A.only when we can see well
B.only when we cannot see perfectly
C.even if we can see dell
D.only when we realize how important our eyes are
People who are near-sighted can only see things that are very close to their eyes.' Everything else is not so clear. Many people who do a lot of close work, such as writing, reading and sewing, become near sighted. Then they have to wear glasses in order to see distant (远处的) things clearly.
People who are far-sighted suffer from just the opposite problem. They can see things that are far away, but they have difficulty in reading a book unless they hold it at arm's length. If they want to do much reading, they must get glasses, too.
Other people do not see clearly because their eyes are not exactly the right shape. They have what is called astigmatism (散光). This, too, can be corrected by glasses. Some people's eyes become cloudy because of cataracts (白内障). Long ago these people often became blind. Now, however, it is possible to operate on the cataracts and remove them."
Having two good eyes is important for judging distances. Each eye sees things from a slightly different angle (角度). To prove this to yourself, look at an object out of one eye; then look at the same object out of the other eye. You will find the object's relation to the background (背景) and other things around it has changed. The difference between these two different eye views helps us to judge how far away an object is. People who have only one eye cannot judge distance as people with two eyes.
We should take good care of our eyes ______.
A.only when we cannot see perfectly
B.only when we can see well
C.even if we can see well
D.only when we realize how important our eyes are
此题为判断题(对,错)。
Having two eyes, instead of one, is particularly useful for ______.
A. seeing at night
B. seeing objects far away
C. looking over a wide area
D. judging distances