Tina and Mark noticed similar changes in their 14-year-old daughter. “She used to cuddle up (蜷伏)with me on the sofa and talk,” said Mark. “Now we joke that she does this only when she wants something. Sometimes she wants to be treated like a little girl and sometimes like a young lady. The problem is figuring out which time is which. ”

    Before age 11, children like to tell their parents what's on their minds. “In fact, parents are first on the list.” said Michael Riera, author of Uncommon Sense for Parents with Teenagers. “This completely changes during the teen years.” Riera explained. “They talk to their friends first, then maybe their teachers, and their parents last.”

    Parents who know what's going on in their teenagers' lives are in the best position to help them. To break down the wall of silence, parents should create chances to understand what their children want to say, and try to find ways to talk and write to them. And they must give their children a mental break, for children also need freedom, though young. Another thing parents should remember is that to be a friend, not a manager, with their children is a better way to know them.

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    Our lifestyles today are very busy. We have family, school, sports, entertainment and social activities to fit into a time that seems never enough. We need to be healthy to meet the demands of daily life. But what does it mean to have a healthy lifestyle?

To have a healthy lifestyle, we need to:

◆ eat different kinds of healthy food most of the time

◆ do exercise often

◆ have time to relax

◆ get enough sleep to give our bodies time to grow healthy and strong

Read about a normal day in the lives of two children.

    No matter which kind of lifestyle you agree on, just remember it's important to balance all aspects of life.

    Elizabeth Blackwell was the first woman doctor in the United States. Her success opened the way for other women who wanted to do more than nursing. She was born in England in 1821 and her family moved to America when she was eleven years old.

    The Blackwell girls received the same education as their brothers. This was most unusual in those days. Their father died young and they had very little money to live on. Elizabeth and her sisters taught at school. Then a woman dying of cancer urged Elizabeth to study medicine, saying that a woman doctor would have saved her from her worst sufferings. Nearly everyone said a girl should not go to medical school, but she managed to enter Geneva College in New York State. She graduated in 1849 at the head of her class and received the first medical degree ever given to a woman.

    Next, Dr. Blackwell went to Paris. Her only chance of training was in a hospital where women came to have their babies. Four months later, while she was working in the French hospital, her left eye became dangerously infected (感染). She lost the eye. She was very disappointed. But she was soon back at work again, this time in London, England. There she met many famous scientists.

    In 1859, Elizabeth Blackwell was officially recognized as a doctor in Great Britain — the first woman to be honored. She was the inspiration of Elizabeth Garrett, who began the women's medical movement in England. Florence Nightingale, founder of the practice of nursing by women, was another of her friends.

    Dr. Blackwell died in 1910 at the age of 89.

    Your next Saturday night takeaway could be brought to you by a robot after a major food delivery company announced plans to use automated vehicles to transport meals. Europe's biggest online takeaway food company Just Eat has partnered with Starship Technologies to deliver food with robots on the streets of London later this month. “Nobody has ever done deliveries with land-based robots,” said Allan Martinson, the chief operating officer of Starship.

    The robot courier can travel up to 4 miles per hour for about 10 miles. It uses a GPS signal and nine cameras to navigate (确定方向). Instead of a person arriving at their door, customers could find themselves receiving a notification (通知) on their phone that says a robot is on its way and a code to unlock the automated courier. “Put the code in, the robot opens up, and there's your food,” said David Buttress, chief manager of Just Eat.

    The robot, which has so far been tested in Greenwich, Milton Keynes and Glastonbury, costs ￡1 to transport within 3 miles, compared with the ￡3 to ￡6 it costs for a human courier. To date 30 robots have driven nearly 5,000 miles without getting into an accident or finding themselves picked on by passers-by. They have driven in more than 40 cities around the world, including London and Tallinn, Estonia.

    An initial worry was how the public would react to robots. But Martinson said the public has been calm when passing the delivery machine on the streets. “The most surprising reaction has been the lack of reaction,” said Martinson.

    Another significant fear was that people would disrupt (扰乱) the robots, or try to steal them and their contents. To prevent this, the robot is fitted with nine cameras, two way audio, and movement sensors that send a warning if it is lifted off the ground. And it opens only with a pass code provided to the customer via a notification. “It's much easier to shoplift than it is to steal a robot,” said Martinson.

    Today just as technology changed the face of industry, farms have undergone an "agricultural revolution". On the farm of today, machines provide almost all the power.

    One of the most important benefits will be the farm computer. The computers help them keep more accurate records so they can make better decisions on what crops to plant, how much livestock (家畜) to buy, when to sell their products, and how much profit they can expect. Many computer companies have been developing special computer programs just for farmers. In the future, farmers will be able to purchase computer programs made to their needs. Because of the growing importance of computers on the farm, students at agricultural colleges are required to take computer classes in addition to their normal agricultural courses. There can be no doubt that farmers will rely on computers even more in the future. While the old-time farm depended on horse power, and modern farms depend on machine power, farms of the future will depend on computer power.

    Another technological advance which is still in the experimental stage is the robot, a real "mechanized hired hand" that will be able to move and, in some ways, think like a human being. Agricultural engineers believe that computer-aided robots will make big changes in farming before the end of the century. Unlike farmers of the present, farmers of the future will find that many day-to-day tasks will be done for them. Scientists are now developing robots that will be able to drive tractors, and harvest fruit. Even complex jobs will be done by robots. For example, in order to milk their cows, farmers must first drive them into the barn, then connect them to the milking machines, watch the machines, and disconnect them when they are finished. In the future, this will all be done by robots. The complete mobilization (活动) of the farm is far in the future, but engineers expect that some robots will be used before long.

Scientists at the Department of Energy's Lawrence Berkeley National Laboratory and the California Institute of Technology have-in just two years-nearly doubled the number of materials known to have potential for use in solar fuels.

They did so by developing a process that promises to speed the discovery of commercially viable (商业可行性) generation of solar fuels that could replace coal, oil, and other fossil fuels.

Solar fuels, a dream of clean-energy research, are created using only sunlight, water, and carbon dioxide. Researchers are exploring a range of possible target fuels, but one possibility is to produce hydrogen by splitting water.

Each water molecule (分子) consists of one oxygen atom and two hydrogen atoms. The hydrogen atoms are extracted, and then can be reunited to create highly flammable hydrogen gas or combined with CO 2 to create hydrocarbon fuels, creating a plentiful and renewable energy source. The problem, however, is that water molecules do not simply break down when sunlight shines on them-if they did, the oceans would not cover most of the planet. They need a little help from a solar-powered catalyst (催化剂).

To create practical solar fuels, scientists have been trying to develop low-cost and efficient materials that perform the necessary chemistry using only visible light as an energy source.

A new method was developed through a partnership between the Joint Center for Artificial Photosynthesis (JCAP) and Berkeley Lab's Materials Project, using resources at the Molecular Foundry and the National Energy Research Scientific Computing Center (NERSCC). JCAP focused on developing a cost-effective method of turning sunlight, water, and carbon dioxide into fuel. It is led by Caltech with Berkeley Lab as a major partner. The Materials Project is a program based at Berkeley Lab that aims to remove the guesswork from materials design in a variety of applications.

"What is particularly significant about this study, which combines experiment and theory, is that in addition to identifying several new compounds for solar fuel applications, we can also learn something new about the basic electronic structure of the materials themselves." says Neaton, the director of the Molecular Foundry.