Where does the conversation probably take place?
A.In a library. B.In a bookstore. C.In a teaching building.
How does the man feel about the article in the end?
A.Satisfied. B.Annoyed. C.Bored.
Which floor is the Committee Room on?
A.The second floor. B.The third floor. C.The fourth floor.
Where did the man put the woman’s bike?
A.Under a street lamp. B.In a garage. C.In a backyard.
请认真阅读下面短文，并按照要求用英语写一篇150词左右的文章。
下图记叙的是一位种树人带着小狗Doggy 去种树时发生的事情, 假定你是下图中的种树人, 以第一人称写一篇150词左右的记叙文。
参考词汇: 桶pail 铲shovel
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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.
Brief1. | People living in a particular2.usually have the same skin color and there are many different skin colors in the world. |
Reason for skin color | The reasons for different skin colors mainly3.in biology and history. |
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. |
Historical reasons | The earliest people in Africa hioknj006Dad dark skin with hair covering it because the sunlight is very strong. |
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. |
