You may have heard adults say they are uncomfortable in the morning without a cup of coffee. One reason they may feel that way is that coffee contains caffeine(咖啡因). Caffeine appears naturally in coffee, tea, and cocoa beans, which are used to make chocolate. But now food makers are adding it to many products, from potato chips to water.

    The US government is especially worried about the problem. That's why the Food and Drug Administration (FDA) is studying the health effects of caffeine on young people. Studies show that too much caffeine can make people nervous and unable to sleep. What's more, caffeine is habit-forming. Those who consume it regularly and stop suddenly may experience headaches and feel tired.

    One of the biggest concerns is the large amount of caffeine added to so-called energy drinks, like Red Bull. A 12-ounce can of cola has about 35 milligrams of caffeine. A similar serving of Red Bull contains more than three times that amount.

    The Institute of Medicine is also working on caffeine-safety measures. “Teenagers should not drink beverages that contain caffeine. They should be aware of caffeine's effects on health and on how the brain works. Take, for example, teenagers who consume caffeine to stay awake and study for a test. They will remember less of what they just studied,” said Stallings, a member of the institute.

    Companies that make products with added caffeine claim they do not advertise them to kids. However, there is no law to stop children from buying them. So the FDA needs to set limits on caffeine, especially in energy drinks. As for added caffeine in foods, the government should just say no. If not, the amount of caffeine should be printed on food labels to remind consumers. The government must do that.

    Doctors say kids should avoid caffeine. If you need extra energy, try these natural boosters: eat right, exercise, and get plenty of sleep.

Holidays

    Think plants are just boring green things that you use for food and decoration? Think again! Plants are able to do some pretty awesome things that you're probably totally unaware of.

    Researchers have discovered that plants have the ability to communicate with an underground network made up of fungus (真菌) , which serves the plants in many ways. Tomato plants use the fungus web to warn each other of their own unhealthy conditions. Trees connected through the fungus network could move nutrients (养分) to and from each other. It is believed that larger trees move nutrients to smaller ones to help them to survive.

    Not only that, but they can also damage unwelcome plants by spreading poisonous chemicals through the fungus. It sounds like the plant world had the Internet before we did.

    Some plants have a rather impressive line of defense against being eaten. When sensing they are being swallowed, they give off a chemical into the air that attracts the insect's natural enemy. The enemy attacks the bug, thus saving the plants. This is basically the plant kingdom version of getting your older brother to beat up that kid who steals your lunch money.

    You might be aware that humans and animals have an internal clock. But did you know that plants also have this clock? This means they can prepare for certain times of day just like we do. Is it because they can react to light at sunrise? In a study, scientists found that plants use the sugars they produce to keep time, which help to regulate the genes responsible for the plant's own internal clock. So, in a sense, wake up with petunias (矮牵牛) is just as valid as ―wake up with the chickens.

    Nature is full of surprises. So for those of you who didn't know the wonders of plants, now you do.

    When a driver slams on the brakes to avoid hitting a pedestrian crossing the road illegally, she is making a moral decision that shifts risk from the pedestrian to the people in the car. Self-driving cars might soon have to make such ethical (道德的)judgments on their own — but settling on a universal moral code for the vehicles could be a tough task, suggests a survey.

    The largest ever survey of machine ethics, called the Moral Machine, laid out 13 possible situations in which someone's death was unavoidable. Respondents were asked to choose who to spare in situations that involved a mix of variables: young or old, rich or poor, more people or fewer. Within 18 months, the online quiz had recorded 40 million decisions made by people from 233 countries and territories.

    When the researchers analyzed these answers, they found that the nations could be divided into three groups. One contains North America and several European nations where Christianity has been the dominant (占支配地位的)religion; another includes countries such as Japan, Indonesia and Pakistan, with strong Confucian or Islamic traditions. A third group consists of countries in Central and South America, such as Colombia and Brazil. The first group showed a stronger preference for sacrificing older lives to save younger ones than did the second group, for example.

    The researchers also identified relationships between social and economic factors in a country. They found that people from relatively wealthy countries with strong institutions, such as Finland and Japan, more often chose to hit people who stepped into traffic illegally than did respondents in nations with weaker institutions, such as Nigeria or Pakistan.

    People rarely face such moral dilemmas, and some cities question whether the possible situations posed in the online quiz are relevant to the ethical and practical questions surrounding driverless cars. But the researchers argue that the findings reveal cultural differences that governments and makers of self-driving cars must take into account if they want the vehicles to gain public acceptance.

    At least Barbara Wage, who heads a group working on autonomous-vehicle ethics at Audi in Ingolstadt, Germany, says such studies are valuable. Wage argues that self-driving cars would cause fewer accidents, proportionally, than human drivers do each year—but that people might focus more on events involving robots.

    Surveys such as the Moral Machine can help to begin public discussions about these unavoidable accidents that might develop trust. "We need to come up with a social consensus," she says, "about which risks we are willing to take."

    I was so fortunate today to be able to offer my love and help to an older lady at my local supermarket. I saw her standing there. I felt quite strange about such a situation.

    What was she looking at? As I looked, I found it was a "Shredded Pork Bun Meal Kit", which is a service that sends customers food ingredients and recipes for them to prepare their own fresh meals. "That's new," I thought. Then I watched as the lady began to dig into her handbag and tried to pull out one of the biggest magnifying glasses (放大镜) I had never seen in my whole life! "Oh, she can't read it," I realized.

    So I stood there and continued watching her. The voice in my mind often asks me to do the right thing. It told me to help her. But I argued back saying, "No. I won't offer help. It will only embarrass her and she is OK now anyway. She has the world's biggest magnifying glass to help her！"

    And I stood there longer. But the voice came back, "Help her, Nicole. Don't be embarrassed. Just do it. Offer your help." So I did it. I read and explained all the things that were included in that box. I read out the ingredients, the instructions on how to cook it and so on.

    She didn't end up buying it, but she was still quite grateful. I walked away knowing that I had helped her and made the right choice. Mostly, I had reminded her that people in this world still care about the old.

    She was seen. She was loved. And she mattered so much that a complete stranger took time to help her. And that stranger was me, a person who argued and didn't want to do so in the beginning.

    So grateful I am when I choose to listen to the voice in my heart. It is because of love. Love is all that ever really matters. I also get happiness through helping her.

增加：在缺词处加一个漏字符号（）并在其下面写出该加的词。

删除：把多余的词用斜线（\）划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

注意：

1. 每处错误及其修改均仅限一词；

2. 只允许修改10处，多者（从第11处起）不计分。

In order to bring down the number of accident and make drivers aware of the danger of driving much fast, many speed cameras are fixed on the roads. Most of them were placed in bright yellow boxes, so drivers can see it clearly from a distance and slow down. On other hand, some officials have the opposite ideas.They believe hiding cameras are more effective than visible ones. The reason is because drivers, not knowing the exact locations of the cameras, will drive more cautious. The police are now gathered related data to make sure which is good.