题目内容
E
When an ant dies, other ants take it out of the nest, often within an hour after its death. This behavior interests scientists and they wonder how ants know for sure—and so soon—that another ant is dead.
One scientist recently came up with a way to explain this ant behaviour. Dong-Hwan Choe is a biologist, a scientist who studies animals and plants. He found that ants have a chemical on the outside of their bodies that signals to other ants, “I'm dead—take me away” when it is dead.
But there's a question to answer: As we know, if an ant is dead, it stops moving. But when an ant is sleeping or knocked unconscious, it is also not moving. However, other ants don't move the living ant out of the nest. How do they know this ant is not dead? Choe found that ants have another chemical on their bodies, which tells nearby ants something like, “Wait—I'm not dead yet”when it is not dead. Choe suspects that when an ant dies, the chemical that says, “Wait I'm not dead yet”quickly goes away. When other ants detect the“dead”chemical without the“not dead yet”chemical, they move away the body.
To test his theory , Choe and his team put different chemicals on ants. When the scientists used the “I'm dead” chemical, other ants quickly moved the treated ant away. When the scientists used the“Wait—I'm not dead yet”chemical, other ants left the treated ant alone. Choe believes this behavior shows that the“not dead yet”chemical overrides the“dead” chemical when picked up by other ants. And that when an ant dies, the “not dead yet” chemical fades away. Other nearby ants then detect the remaining“dead”chemical and remove the body from the nest.
Understanding this behavior can help scientists figure out how to stop ants from invading new places and causing problems.
57. What is the function of the first paragraph?
A. Leading the following paragraphs.
B. Showing the main idea of the passage.
C. Introducing the background of the passage.
D. Giving a summary of the passage.
58. Which of the following has the closest meaning to the underlined word “overrides” in the fourth paragraph?
A.is weaker than B. is stronger than C. is better than D. is worse than
59. What can we learn from the passage?
A. Living ants can also be taken away when they are not moving.
B. When an ant dies, it can tell others using a certain chemical.
C. A living ant can pretend to be dead using a special chemical.
D. Ants often use chemicals to communicate with each other.
60. Which of the following descriptions about Dong-Hwan Choe is right?
A. Choe did this study in order to stop ants from invading new places.
B.Choe is a biologist who is only interested in animals, especially in ants.
C. Choe first came up with an idea to explain this ant behavior,and then did some tests to prove his theory.
D. Choe did the research on this ant behavior on his own
57-60 ABBC
解析
E
When I was growing up, 16 was always a magical age, a symbol of maturity, responsibility and of course more independence and freedom. I sat through the hours of Driver’s Ed classes eager to get out on the road. I couldn’t wait to get my driver’s license.
But it’s a different story for today’s teens. In January, the U.S. Department Transportation released 2012 data that showed only 30.7 percent of U.S. teens got their license at age 16, Twenty years before, that number was almost 45 percent.
There are numbers of reasons for the fall – off. The growing responsibilities like paying for insurance and high gas prices discourage teens from getting behind the wheel. Plus, many teens today are so busy with homework, endless hours of activities and part-time jobs, that finding the time for Driver’s Ed classes may be more difficult that ever.
In addition, many states have raised the driving age, or restricted when teens can drive and who they can have in the car. Parents may also be making their own personal restrictions until they feel their teens are responsible enough to drive safely.
Driving is part of the American culture, but it’s not the central focus like it was 25 years ago. They have so many other things to do now. One of the more interesting factors delaying teens driving might be the change of their social life. Today, teens need to look no further than Face book or other social networking sites to connect with their friends. There is simply less need, maybe less desire, to be able to grab the keys and go.
Michelle Wei got her license as a senior in high school because her digital social life made it easy no to drive. “If I couldn’t get a ride to see my friend who lives a town over,” the 19-year-old said, “I could talk on IM or Skype.”
Research has shown that these online relationships can lead to higher quality friendships, so it isn’t necessarily a bad thing. However, it’s important to find a balance. If old face-to-face friendships are good, why not drive to find them?
【小题1】We can infer from the first paragraph that .
A.Driver’s Ed classes allowed teens to know what maturity was |
B.getting a driving license at 16 was a must for American teens |
C.16 was considered an age when one could get his driver’s license |
D.teens could drive on the road without taking Driver’s Ed classes |
A.Desire to drive on the road declines among American teens. |
B.Getting a license costs much more than ever before. |
C.Social networking sites are changing the life of American teens. |
D.American teens are becoming more responsible than ever. |
A.why American teens are crazy about digital social life |
B.what social networking websites are bringing to American teens |
C.to what degree the Internet is affecting the American car culture |
D.what the Internet does to help teens to get a driving license |
A.the Internet h as a bad effect on the teen’s social life |
B.teens should keep a balance in choosing their lifestyle |
C.actual contacts can be replaced by talking on line |
D.face-to-face friendship is always the best choice |