Hello. I'm Jan from Mrs. Lake's class. My class wants to work together to help the public. We think we have found a great way to do this. Last month we did a class project on the highways near our town. We learned about the Adopt-a-Highway Program. This program brings people together to pick up litter along the roads. We think it would be a great idea for all students in our school to join the program and adopt a highway.

    Adopting a highway is not like adopting a pet. When a highway is adopted, only part of the highway is cared for by a group of people. The group agrees to work every week to keep its part of the highway clean. Each group gets its own sign that has the name of the group printed on it. The sign is put up at the side of the road. This sign lets drivers know who is keeping that area of the road clean.

    The Adopt-a-Highway Program is a great way for people to help their environment look nicer. Also, the government does not have to send out as many road workers. This saves money. Finally, people may try harder to keep roads clean if they see people, especially teenagers like us, cleaning them up.

    We will need helpers to care for our adopted highway. If you want to feel great and keep our roads clean，please come with your parents to the meeting next week. We will meet in Mrs. Lake' room on Wednesday at 6:00 P.M. At the meeting, we will talk about which roads are the dirtiest as a result of people's unkind acts. Then we' ll try to pick an area to adopt and clean.

    I look forward to seeing you at the meeting. Remember to keep our roads clean!

    If doctors want to test you for something, they'll usually take a blood or urine sample. But wouldn't it be much more convenient if they just asked you to breathe through a special instrument?

    In fact, your breath can say a lot about you. In traditional Chinese medicine, doctors draw a conclusion about the health state of a patient based on the smell of his or her breath; trained dogs and rats can identify the smells of the breaths of people suffering from certain cancers; traffic police also monitor drivers' alcohol consumption by testing their breaths.

    Just like blood and urine, your breath contains lots of “metabolites” —the waste chemicals that the body produces, which vary from person to person. They are like personal health fingerprints, which is why scientists sometimes call them “breathprints”, according to Science Daily.

    Compared to blood or urine testing, breath testing takes only seconds instead of hours, and it requires neither a needle nor a container to hold the body fluids(液). This means the test can be taken frequently to better detect early signs of diseases and monitor the progress of a medical treatment.

    On the other hand, as an identifier, you might think that breaths are not as reliable as fingerprints since they might change based on what you eat. However, researchers in Zurich, Switzerland mapped 11 healthy volunteers' chemical patterns by having them breathe through a special instrument, and they found that each pattern was unique and the patterns didn't change much throughout the day, reported BBC.

    “Our goal is to develop breath analysis to the point where it becomes competitive with the established analysis of blood and urine,” said Malcolm Kohler, professor at the University Hospital Zurich.

    Robots and humans will soon be living in harmony(和睦).A singing robot is being taught to create jazz with a human in a project.

    Antonio Chella from Italy is working with a Telenoid robot. To start with, the Telenoid will be trained to follow the movements and simple sounds made by a human singer, and to connect music with different emotional states. Chella then plans to see if the robot can use these connections to create music.

    Intelligence is often regarded as the ability to find connections between the existing things. But Chella suggests that a conscious(有意识的) creature should be able to go a step further and introduce new connections that result in the creation of something new.

    Some jazz musicians say that they should have a mental library of musical phrases so that they are able to combine them in new ways. More importantly, however, this combination happens in a state that is similar in a sense to dreaming. Chella wants to copy these states in a machine.

    “This work raises interesting questions about the link between consciousness and music making,” says Philippe Pasquier, a musician and computer scientist. But he is skeptical about whether a robot musician needs a physical body.

    Pasquier argues that the robots are faced with two challenges(挑战). Software that can copy Bach has already been developed. But interpretation（演绎）includes human's different tastes and judgments. “What made the Beatles famous was not so much their works, but the fact that the interpretations of the works were wonderful,” he says.

    It is not yet clear how a robot would go about interpreting music in a new way. But by copying humans and then learning to sing, Chella's robot could provide clues.

    What seems to be important is that human composers often listen to lots of music made by others. So Chella's robot had better listen to those jazz standards first.

    This past summer I went on a journey to Canada's Arctic with Students On Ice. When I left Calgary I wondered what I would find what I would learn and who I would meet. On the trip to Ottawa I was wrapped in a blanket of uncertainty and excitement. But when I first met the group of students, scientists and leaders, I knew that l didn't have anything to worry about. The group was amazingly receptive and I was soon part of a big family setting out on an amazing adventure—an adventure of a lifetime!

    When we reached the Arctic I saw a vast Land that appeared untouched and original. I was surprised by its great size and beauty and my senses were repeatedly shocked and amazed. I stood on the Kapitan Khlebnikov and saw twelve polar bears. They walked in search of seal holes, and patiently waited for a meal. I learned that polar bears are successful only one out of every twenty hunting attempts.

    However, I learned that the Arctic and its people are being threatened by pollution and global warming. I learned that pollutants are carried by ocean and air and have a bad effect on all Arctic people. I learned that global warming has put polar bears at risk because a warmer climate means that they have a shorter time to hunt seals on the ice.

    The trip was a feast (盛宴) for the senses. I have learned more about our environment, and particularly how alive and interesting the Arctic is and why it is so important to take care of it. I learned pollution, ignorance of individual and global problems need to be solved. The Arctic deserves to be preserved. My trip with Students On Ice has made me more determined to try to ensure that I do not leave harmful footprints on either Earth or its people.

No one can believe that the over 6, 300-kilometre Great Wall might disappear some day. Believe it or not, the Great Wall is being destroyed by people. Less than 20 percent of the Great Wall built in the Ming Dynasty is still perfect, and about 80 percent is in danger. 

The Great Wall can be called "great" mostly because of its amazing length. If we do nothing to save the Great Wall, it will become wasteland rather than a historic site. The Great Wall is actually a series of walls built and rebuilt by different dynasties over the past 2, 000 years. It began in the Qin Dynasty, and lasted into the Ming Dynasty. The parts built before the Ming Dynasty have nearly disappeared. People are familiar with sections such as Badaling in Beijing and Jiayuguan Pass in Gansu, because they have been open to tourists for many years. But those sections far away from the public eyes have been almost forgotten. 

Few local people knew the 3-metre-high walls made of earth and stones beside them are part of the Great Wall. The lack of knowledge is considered as one of the main reasons behind humans. 

The bricks on the Great Wall are carried off by countryside people to build their houses. Rubbish is spread over the battlements. Those who destroyed and are destroying the Great Wall know its name, but don't know its cultural meaning. The local farmers not only carried off the body of the Great Wall but dug out the entire base. 

It is necessary to protect the Great Wall. First of all, the officials should be aware of the importance of the Great Wall. Young Chinese should know more about the nation's great civilisation and learn to love it. 

Napa Valley is home to some of California's most beautiful hiking trails. Whether you're a seasoned hiker or a beginner, these trails are perfect for a day trip.

Robert Louis Stevenson State Park

Named after the famous author who spent his honeymoon in the area, it offers some of the most scenic hiking trails in Napa Valley. The park features over 5 miles of hiking trails, catering to hikers of all skill levels. You can even see the San Francisco Bay on a clear day.

Skyline Wilderness Park

It is a popular hiking destination in Napa Valley, featuring over 25 miles of hiking trails that offer magnificent views of the valley. On a clear day, you can even see the Golden Gate Bridge. The park is also home to a variety of wildlife, including deer, coyotes and mountain lions.

Westwood Hills Park

It is a hidden gem in Napa Valley. The park boasts over 4 miles of hiking trails, ranging from easy to difficult, making them ideal for a day trip. A wide range of wildlife, including deer and wild turkeys, also lives in this area.

Bothe-Napa Valley State Park

The park is located in the heart of the beautiful Napa Valley wine country and has over 10 miles of trails. It is a paradise for outdoor enthusiasts. It offers easy access to swimming areas and picnic spots. And if you can't get enough of the outdoor activities here, there is a camping site that can be booked for overnight stays.