阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项。

    Green is an important color in nature. It is the color of grass and the leaves on trees. It is also the color of most growing plants.

    Sometimes, the word “green” means young, fresh and growing. For example, a greenhorn is someone who has no experience. In the 15th century, a greenhorn was a young cow or an ox whose horns(角)had not yet developed. A century later, a greenhorn was a soldier who had no experience in war. By the 18th century, a greenhorn had the meaning it has today—a person who is new in a job.

    Someone who is good at growing plants is said to have a green thumb(大拇指). The expression comes from the early 20th century. A person with a green thumb can make plants grow quickly and well.

    Green is also the color used to describe the powerful feeling , jealousy(嫉妒). The green-eyed monster （怪物）is not a dangerous animal from outer space. It is an expression used about 400 years ago by the British writer William Shakespeare in his play “Othello”. It describes the unpleasant feeling when someone has something he wants. For example, a young man may suffer from the green-eyed monster if you get a pay rise and he does not.

    In most places in the world, a green light means to move ahead. In everyday speech, a green light means agree to continue with a project.

    Recently I started discovering one thing which amazes me so much: how perfect everything is in the world we are living in! Just look, all day long we are busy working and just when we get tired, the night comes in, so we may sleep and relax. One day we may enjoy the bright sun and another day, when we get tired of the sun, the rain pours down.

    A few months ago I was so happy with my life. Later, I got tired from the happiness. I wished I would have some trial to strengthen my character and learn something new about life. I got what I wanted. Shortly after I got severe angina (心绞痛), so I had to stay home for several weeks. During this period I had time to rethink my life and discover myself. The lessons were terrific, but I felt grateful for this time.

    Another example: I have a friend, who primarily thinks about having fun. Once I thought why we get along well with each other and what in me attracts her. A couple of days ago I found the answer. I like calmness and silence. She likes noise and agitation (热闹). We attract each other just to balance ourselves, in other words, to give some drive to me and some calmness to her!

    So remember that the universe is so wise that it will try to balance you. As for me, this is perfect because extremes create suffering: too much food – too little food, too cold – too hot, too much fun – too little fun.

    There is no question that fewer teenagers are on the roads in the US.

    In 1978, 50% of 16-year-olds had got their first driving licences. In 2008, according to the US Transportation Department, it was just 30%. The number of those aged 19 and under with driving licences has also been declining since 1978, when 11,989,000 had licences. In 2010, it was 9, 932,441, or 4.1% of American drivers.

    In the UK, 683,273 teenagers have driving licences—just 1.85% of total licence holders, according to Department of Transport figures from September 2010.

    But the decline in the US may have more to do with tougher tests and the introduction of the new rule in many states, which force drivers aged under 16 to be with licensed drivers of 21 years and older when driving.

    In recent years, the annual number of journeys being made by American drivers of all ages has declined clearly for the first time ever. Car use began falling in 2007, when average petrol prices almost doubled to $ 4.12 a gallon, and the economy became worse.

    But there are signs that it is getting back to normal and America remains a country on wheels. It has a higher number of cars per head of population than any other country in the world.

    “Cars will always be a popular means of transportation in America. You have to take into consideration some places don't have access to public transportation. Cars are the only way some people can get around,” says Kristin Nevels. This makes driving necessary in some rural states, where about twice as many teenagers are on the road than in big cities.

    In a recent series of experiments at the University of California, researchers studied toddlers' thinking about winners and losers, bullies (欺凌) and victims.

    In the first experiment, toddlers (学步儿童) watched a scene in which two puppets (木偶) had conflicting goals: One was crossing a stage from right to left, and the other from left to right. The puppets met in the middle and stopped. Eventually one puppet bowed down and moved aside, letting the other one pass by. Then researchers asked the toddlers which puppet they liked. The result: 20 out of 23 toddlers picked the higher-status puppet — the one that did not bow or move aside. It seems that individuals can gain status for being dominant (占优势的) and toddlers like winners better than losers.

    But then researchers had another question: Do toddlers like winners no matter how they win? So, researchers did another experiment very similar to the one described above. But this time, the conflict ended because one puppet knocked the other down and out of the way. Now when the toddlers were asked who they liked, the results were different: Only 4 out of 23 children liked the winner.

    These data suggest that children already love a winner by the age of 21-31 months. This does not necessarily mean that the preference is inborn: 21 months is enough time to learn a lot of things. But if a preference for winners is something we learn, we appear to learn it quite early.

    Even more interesting, the preference for winners is not absolute. Children in our study did not like a winner who knocked a competitor down. This suggests that already by the age of 21-31 months, children's liking for winners is balanced with other social concerns, including perhaps a general preference for nice or helpful people over aggressive ones.

    In a time when the news is full of stories of public figures who celebrate winning at all costs, these results give us much confidence. Humans understand dominance, but we also expect strong individuals to guide, protect and help others. This feels like good news.

    Artificial intelligence can predict when patients with a heart disorder will die, according to scientists.

    The software learned to analyze blood tests and scans of beating hearts to spot signs that the organ was about to fail. The team, from the UK's Medical Research Council, said the technology could save lives by finding patients that need more aggressive treatment. The results were published in the Journal of Radiology.

    According to the researchers, high blood pressure in the lungs damages part of the heart, and about a third of patients die within five years after being diagnosed. There are treatments: drugs, injections straight into the blood vessels, a lung transplant. But doctors need to have an idea of how long patients might have left, in order to pick the right treatment.

    The software was given scans of 256 patients' hearts, and blood test results. When this data was combined with eight years of patient health records, the artificial intelligence predicted when patients would die.

    The software could look about five years into the future. It correctly predicted those who would still be alive after one year about 80% of the time. The figure for doctors is 60%.

    The team now want to test the software works in other patients in different hospitals before assessing whether it should be made widely available to doctors. The researchers also want to use the technology in other forms of heart failure, such as cardiomyopathy, to see who might need a pacemaker or other forms of treatment.

    Dr Mike Knapton, from the British Heart Foundation, said, "This exciting use of computer software in medical practice will help doctors in the future to make sure that patients are receiving the correct treatment before the condition deteriorates and leaves them needing a lung transplant. The next step is to test this technology in more hospitals with heart disease."

Earthquakes are something that people fear.There are some places that have few or no earthquakes.Most places in the world,however,have them regularly (有规律地).Countries that have a lot of earthquakes are usually quite mountainous.

The most talked about earthquake in the United States was in San Francisco in 1906.Over 700 people died in it.The strongest one in North America was in 1964.It happened in Alaska.

Strong earthquakes are not always the ones that kill the most people.In 1755,one of the strongest earthquakes ever recorded was felt in Portugal.Around 2,000 people died.

In 1923,a very strong earthquake hit Tokyo and the Yokohama areas of Japan.A hundred and forty thousand people died.Most of them died in fires which followed the earthquake.

One of the worst earthquakes ever was in China in 1976.It killed a large number of people.The worst earthquake ever reported was also in China,in which about 830,000 people were killed.This earthquake happened in 1556.

Earthquakes worry people a lot.The reason is that we often do not know when they are coming.People cannot prepare for it.