Dujiangyan is the oldest man-made water system in the world, and a wonder in the development of Chinese science. Built over 2,200 years ago in what is now Sichuan Province in Southwest China, this amazing engineering achievement is still used today to irrigate over 6,000 square kilometres of farmland, take away floodwater and provide water for 50 cities in the province.

    In ancient times, the region in which Dujiangyan now stands suffered from regular floods caused by overflow from the Minjiang River. To help the victims of the flooding, Li Bing, the region governor, together with his son, decided to find a solution. They studied the problem and discovered that the river most often overflowed when winter snow at the top of the nearby Mount Yulei began to melt as the weather warmed.

    The simplest fix was to build a dam, but this would have ruined the Minjiang River. So instead Li designed a series of channels built at different levels along Mount Yulei that would take away the floodwater while leaving the river flowing naturally. Better still, the extra water could be directed to the dry Chengdu Plain, making it suitable for farming.

    Cutting the channels through the hard rock of Mount Yulei was a remarkable accomplishment as it was done long before the invention gunpowder and explosives. Li Bing found another solution. He used a combination of fire and water to heat and cool the rocks until they cracked and could be removed. After eight years of work, the 20-metre-wide canals had been carved through the mountain.

    Once the system was finished, no more floods occurred and the people were able to live peacefully and affluently. Today, Dujiangyan is admired by scientists from around the world because of one feature. Unlike modern dams where the water is blocked with a huge wall, Dujiangyan still lets water flow through the Minjiang River naturally, enabling ecosystems and fish populations to exist in harmony.

    In Washington, Virginia and Maryland, the final months of the year have many festivals. Whether you are into a theatre environment, medieval times or a book festival, there is an event for you.

1). Maryland Renaissance Festival

    The festival, now in its 38th season, features 12 stages and hundreds of costumed actors offering entertainment such as music and theatre performance, sword swallowing and a human chess match. Sept. 21 through Oct.19.

2). Baltimore Book Festival in Maryland

    This three-day fair features talks and book signings from more than 275 locally and nationally known authors, including Alice McDermott and Andre Dubus III. The festival also includes live music and literary hands-on projects for kids. Sept. 26-28.

3). Middleburg Film Festival in Virginia

    The festival offers a relaxed theatre environment, and the events include a dancing party, an orchestra performance of horror film music by Marco Beltrami, and a discussion with Colleen Atwood, who is a famous costume designer. Oct. 30 through Nov.2.

4). Temple Hall Corn Maize and Fall Festival in Virginia

    The 286-acre farm offers a lot of family-friendly entertainment, including pig races, farm animals and camel rides. Grab seasonal goods at the farmers' market, take part in the corn harvest, and hear live bluegrass and folk music. Friday through Sunday, Sept. 26 through Nov.2.

5). Kids Euro Festival in Washington

    Here is a chance to celebrate and experience European arts and Culture, no passports required. Twenty-eight European countries will be represented during the multicultural children's event, which features more than 200 performances and workshops. The festival is for children ages 2 through 12, librarians and educators. Activities include puppet shows, cooking and theatre workshops. “It really brings Europe to the children, ” said organizer Sandi Auman. Oct. 24 through Nov. 9

    Phone Soap: Charge and Clean Your Phone

    You may charge your phone every day, but do you clean your phone as much? Whatever your hands touch, your phones touch. It has been discovered that some phones have 18 times more bacteria and viruses than any surface in a public restroom. So it probably won't surprise you that a 2011 University of London study found that one in six of our phones have bacteria and viruses on them—specifically, the bacteria called E. coli.

    The research on bacteria and viruses led to the invention of Phone Soap. It is not actually liquid like dishwasher soap. It is a phone charger that uses the electromagnetic radiation (辐射) used in hospitals to kill 99.9 percent of bacteria and viruses, cleaning your phone while it charges.

    “There are really certain types of bacteria and viruses that we should not be in touch with, and they are really on our phones,” says Wes Barnes, the Phone Soap co-founder. It all started while his cousin and co-founder, Dan LaPorte, was in his cancer research lab at college. “He realized he got the idea of getting rid of bacteria and viruses on the phones,” said Barnes. “In the lab they used UV-C light for destroying them. He realized this would be the fastest, most powerful way to kill any bacteria and viruses living on electronic machines.”

    Phone Soap looks like a little metal suitcase. Your phone rests in to charge and get cleaned at the same time. Instead of plugging your phone into the wall, you'd plug it into the Phone Soap charger box. The process only takes a few minutes but, Barnes says, “The idea is that you can leave it in there overnight if you want to keep charging. Reflective paint keeps the light completely around the phone so it cleans the phone fully.”

    The co-founders spent 2013 finding the right companies and they started shipping the product in late November. By last week's International Consumer Electronics Show in Las Vegas, Phone Soap was all grown-up. Both co-founders have left their previous jobs and are selling Phone Soap nonstop. “We're shipping almost more than we can handle each day,” Barnes says. “It's been a great adventure.”

    Teachers' Day is, interestingly, not celebrated on the same day all over the world. In some countries it is marked by a holiday, in others it is a working day.

    International Teachers' Day is celebrated on October 5. Being held ever since 1994, it is in honor of teachers' organizations worldwide. Its aim is to encourage supports for teachers and to meet the needs of students.

    China In 1939, Teachers' Day was set for August 27, Confucius' birthday. In1951, the celebration was stopped. However, it was founded again in 1985, and the day was changed to September 10.

    India   Teachers' Day is celebrated on September 5 in honour of Dr. Sarvepalli Radhakrishnan, the second president of India, whose birthday falls on that day.

    Russia ― In Russia, Teachers' Day was celebrated on the first Sunday of October between 1965 and 1994. Since 1994, the day is observed on the October 5, just the same day as World Teachers Day.

    The US   In the US, Teachers' Day is non-official holiday. It is celebrated on the Tuesday of the first full week of May. A number of activities are organized in schools to honor teachers. The celebrations can continue for the whole week of May.

    Thailand   In Thailand, National Teachers' Day is celebrated every year on January 16. The first Teachers' Day was held in 1957. The day is a holiday in schools.

    For many people, the Transformers movies are the greatest Hollywood blockbusters (大片). And among the Transformers themselves, the yellow Autobot named Bumblebee is certainly the favorite. He may be one of the smallest and weakest of the alien machines, but he is always loyal to his friends and shows great bravery in battle.

    In the new film, Bumblebee is found in a junkyard (废车场) and is full of honeybees. He always finds himself in awkward (尴尬的) situations, but people like his cute and naive looks. In addition to his blue eyes, Bumblebee's body language and movements are adorable. At one point, he sits with his legs straight out, with his huge feet making him look like a 5-year old trying on his dad's shoes.

    Bumblcbee is the Transformer who has the greatest affinity (亲和力) with humans. He starts journey with Watson, who is at a loss about her future and wants a friend. As a result of their adventure together. Watson grows up and starts to work toward her life goal of becoming a musician. As for Bumblebee, as we know, is a robot from outer space, he now has a better understanding of his task to protect the Earth. Every adventure has a beginning, as the movie poster puts it. More importantly, every adventure needs a good partner. The considerate, positive and warm Bumblebee is definitely a good choice according to US actress I Hailee Stcinfeld, who plays Watson in the film.

Doing crosswords(纵横字谜) is a fun way to kill the time and can also be educational. Difficult crosswords may leave you confused as you have no ideas on how to solve them sometimes. To perform well in this game, you need to have enough knowledge of different fields. If you are unable to do them and you have access to the answers, it is not generally considered cheating to look up an answer or two. However, in some cases, it does not follow the rule.

A crossword should not include someone else's answers, so even a quick look at a fellow student to complete a crossword would not be fair. Generally, you wouldn't have access to the answers.

Additionally, some crossword competitions should not be connected with cheating. Again, in such a situation, you usually won't have access to the answers. Turning to the Internet or referring to(查阅) any books of crosswords for answers is also unfair, since some people will complete the crosswords strictly with their own knowledge.

If you are not in a competitive environment, the check of a word can actually be an opportunity to learn how to become better at crosswords. Through looking up the answers (Although sometimes considered as cheat.), you can memorize whatever facts or word definitions (定义) you must look up. This will help you avoid the need to cheat in the future.

Some argue that cheating on crosswords is always wrong, and you're only cheating yourself if you are looking up the answers. It could be argued instead that cheating on crosswords that are done for fun or enjoyment can actually be an opportunity to benefit yourself because you're learning something new. Just don't forget to mention that you actually did cheat a little. Being honest is of great importance both to you and the other competitors.

It can be helpful to buy books of crosswords that have several different difficulty levels. If you are new to doing crosswords, you might want to put off working on crosswords until you are more confident in your skills.