题目内容
B. usually
C. hardly
D. almost
天天练口算系列答案“This is the BBC News at Eight O’ Clock.”
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“Chinese people spent about 120 billion yuan during the first three days of the May Golden Week last year. This year it has increased to 140 billion yuan.”
“The children of Beijing No.2 Middle School sang with students from Toronto in Canada to celebrate the 20thanniversary. They had been sister schools since 1986. They spent about two weeks together in Beijing. They visited the Great Wall and the Summer Palace. They took a lot of photos in Beihai Park.”
“Have you ever got tired of heavy shopping bags? A new shopping assistant robot which was invented by Japanese company could be the answer. The helpful robot can follow you around and carry several bags. The robot was tested at a shopping center in February 2006. ”
“About 500 people from different countries were in the 2006 “Rock Paper Scissors(剪刀)” World Match in Canada. This event was founded in 1842. It is said playing this game is fun, and also a good way to solve problems among people.”
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“And now it’s time for Morning Music.”
1.The students from Canada and Beijing No. 2 Middle School didn’t ________.
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A．take photos |
B．visit the Great Wall |
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C．visit the Summer Palace |
D．have a football match |
2.This year during the first three days of the May Golden Week, it cost Chinese people ___________ yuan more than that of last year.
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A．260 billion |
B．120 billion |
C．140 billion |
D．20 billion |
3.Which of the following is not talked about in the news?
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A．The robot can help with shopping bags. |
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B．A Japanese company invented the robot. |
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C．The robot was tested at a shopping centre. |
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D．There are such robots in people’s homes now. |
4.The underlined word “anniversary” means .
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A．founding |
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B．yearly return of the date of an event |
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C．university |
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D．the new beginning of something important |
5.Which of the following is a game?
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A．Rock Paper Scissors |
B．May Golden Week |
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C．Shopping assistant robot |
D．A visit to the school |
Have you ever wondered why there are so many skin colors in the world? Do you know why people living in particular areas usually have a certain color? Biology and history are the two reasons for this.
Skin contains something called melanin, which determines a person’s skin color. The more melanin a person has, the darker his or her skin will be. The amount of and the production of melanin are controlled by genetics, but can be affected by other things, such as sunlight. If a person lives in a place with less sunlight, a person’s body will produce less melanin, making the skin lighter.
Skin color is also affected by another source ---- vitamin D. humans all need vitamin D to build bones. People can get it by eating foods such as fish and milk, or from sunlight, so sunlight absorbed by melanin cannot be used for vitamin D production. Therefore, a dark—skinned person will produce less vitamin D than a light—skinned person when they received the same amount of sunlight.
The connection between vitamin D production and skin color is clear when we look at evolution. The earliest humans lived in Africa, their dark skin produced less vitamin D because of their dark skin. As a result, their skin made less melanin, so they could get enough sunlight to produce vitamin D. their skin gradually got lighter and they lost hair. Now, people living in areas with strong sunlight like Africa, have darker skin, while people living in other areas have lighter skin. The exception to this is the Inuit, who live in a place with little sunlight, but have dark skin because they eat a lot of fish and have enough vitamin D.
Evolution has given us a rainbow of skin colors. Humans have always had melanin to determine our skin color. What has changed through history is the environment where we have lived. This has in turn changed our melanin production, and eventually, skin color.
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Brief 1 |
People living in a particular 2 usually have the same skin color and there are many different skin colors in the world. |
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Reason for skin color |
The reasons for different skin colors mainly 3 in biology and history. |
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Biology reasons |
The amount of melanin, by which a person’s skin color is __4 , varies from people to people. The more melanin a person has, the __5 his or her skin will be. Vitamin D is another source 6 skin color. Vitamin D is necessary for humans to build bones. Sunlight contributes to vitamin D in the skin. |
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Historical reasons |
The earliest people in Africa hioknj006Dad dark skin with hair covering it because the sunlight is very strong. When they moved to places where they could not get enough sunlight to __7___ vitamin D, their skin color became lighter. Generally speaking, people in areas with strong sunlight, have darker skin ____8 people in other areas have lighter skin. |
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9 |
Melanin 10 an important role in our skin color. With our living environment changing, melanin production is changed, which leads to the changes in our skin color. |