题目内容
______ from other continents for millions of years, so it has many plants and animals that cannot be found anywhere else in the world.
A. Having been separated B. Separated
C. It has been separated D. Having separated
C
名校课堂系列答案The price of milk may be going up. There was not enough rain in some parts of the country last year and the bad weather may mean that a gallon (加仑) of milk will cost 41 cents more after October 1st.
California already has high milk prices and the California court does not want the price to go any higher. High milk prices will be very hard for some people. Families with many children will have to spend more money to buy milk. The poor and older people without much money will also be hurt by higher prices.
The court said that more milk from other states should be sold in California as the price of milk from other states is not as high. Some states got enough rain so their costs did not go up. People will then be able to buy the cheaper milk, meaning that unless milk producers bring their milk prices down, their milk will not sell.
The drought (干旱) around the country has meant market forces are likely to push milk prices up by as much as 41-cent a gallon by October 1st. Experts said this decision by the Californian court could reduce (减少) the effect of the price rise here.
The 41-cent increase would add to California’s already high milk prices so California must allow more milk producers from outside the state to sell their products there. This would then lead to increased supplies (供应), which would, as a result, stop milk prices from increasing.
1.Who will be hurt by high milk prices?
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A．Young people. |
B．Milk producers from outside California. |
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C．Rich people. |
D．Families with lots of children. |
2.What caused milk prices in California to increase?
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A．Short supplies from other states. |
B．Being short of rain. |
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C．The California court. |
D．Children’s need for milk. |
3.What will California do to keep milk prices down?
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A．Force milk producers to lower their price. |
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B．Encourage people to drink less milk. |
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C．Get men to produce more rain. |
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D．Increase the supply of milk in the state. |
It takes years of school to develop math skills, but learning about numbers starts earlier than you might think. Now according to a new study, at three months, babies have already started acquiring a concept (概念) of “how much”.
Previous research had suggested that very young babies can tell when the number of objects (物体) in a group has changed. But the babies in these studies were simply reacting generally to the fact that something had changed, they suspected.
Researchers of Harvard University studied 36 babies, all three months old. During the tests, each baby wore a hat with sensors (传感器). The babies watched a series of images on a computer screen. They showed the same object, such as a cartoon character. For a while, the number of the objects in the pictures didn’t change. Then the images began to display a different object, or a different number of one of the objects the babies had previously looked at. As soon as something changed, the babies’ brains responded with a specific pattern of electrical signals, which would be recorded by sensors.
By analyzing these signals, the researchers discovered that one part of the brain (near the top on the left side) responded when the object in the image changed. A different part of the brain (lower and on the right side) responded when the number of objects in the image changed. This was not the area of the brain that is involved in attention. That suggests that the babies’ brains are doing more than just reacting to a change in what they’re seeing – they actually seem to be able to tell number changes from other types of changes.
Numbers and amounts are important concepts in our lives. Even though babies are years away from adding, subtracting (减), multiplying, and dividing, their brains seem to be preparing for a time when they finally will.
1.Why were hats with sensors used in the study?
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A．To record the images on the computer screen. |
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B．To remind babies of the changes of numbers. |
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C．To record the electrical activity of each baby’s brain. |
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D．To help babies concentrate on the computer screen. |
2.What does the underlined word “They” in the third paragraph refer to?
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A．Babies involved in the study. |
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B．Sensors worn by the babies. |
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C．Numbers marked on the objects. |
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D．Images shown on the computer screen. |
3.Which part of the brain is responsible for responding to the changes of numbers?
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A．The top. |
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B．The left side. |
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C．The lower and the right side. |
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D．The upper and the left side. |
4.The last paragraph mainly implies that .
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A．babies are in fact cleverer than they are thought |
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B．it is impossible to understand human brain completely |
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C．numbers play the most important part in people’s lives |
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D．the ability of babies remain a mystery to scientists |
5.The purpose of the study is to prove that .
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A．math skills should be developed as early as possible |
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B．numbers are easier for babies to judge than images |
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C．babies really do have some sense of numbers |
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D．babies can react differently to what they see |