The first living creatures to travel in space were the dogs of the Soviet Unions space program.Beginning in 1951 dogs flew aboard sub－orbital flights to the height of 63 miles and higher.They helped to test the equipment that would later be used by humans.The first pair of dogs to fly，on July 22，1951，were named Tsygan and Dezik.

     Space dogs would make history on November 3，1957.On this date，just one month after the historic launch of the world's first artificial satellite，Sputnik，the Soviet Union shocked the world again by launching Sputnik 2.This satellite contained the first living creature to travel in space，a dog named Laika.Laika was to have orbited for a week or more until her food and oxygen ran out.In fact，Laika lasted only hours in orbit before over heating in her capsule(太空舱) took her life.

     That next step，occurred in August 1960，when the dogs Belka and Strelka made 18 orbits of earth and returned alive.Like Laika before them，they became distinguished ， featured in newspapers and magazines around the world.

     Six more orbital dog flights over the next eight months further tested the equipment necessary for humans to follow in the dogs' footsteps.That historic event happened on April 12，1961，when Yuri Gagarin became the first human to travel in space.

     The role of the space dogs had proven important in advancing the exploration of space.But，they would make one final flight.In 1966，traveling aboard the Cosmos 110 satellite，the dogs Ugolek and Veterok spent 22 days in orbit.Once again dogs led the way.Humans would not achieve a space flight that long for eight more years，in Skylab 2.

    One day, a poor man, who had only one piece of bread to eat, was walking past a restaurant. There was a large pot of soup on the table. The poor man held his bread over the soup, so the steam from the soup went into the bread, and gave it a good smell. Then he ate the bread.

    The restaurant owner was very angry at this, and he asked the man for money, in exchange for the steam from the soup. The poor man had no money, so the restaurant owner took him to Nasreddin, who was a judge at that time. Nasreddin thought about the case for a little while.

    Then he took some money from his pocket. He held the coins next to the restaurant owner's ear, and shook them, so that they made a dingling (叮当声) noise.

    “What was that?” asked the restaurant owner.

    “That was payment for you,” answered Nasreddin.

    “What do you mean? That was just the sound of coins!” said angrily the restaurant owner.

    “The sound of the coin is payment for the smell of the soup,” answered Nasreddin. “Now go back to your restaurant.”

    Almost every machine with moving parts has wheels, yet no one knows exactly when the first wheel was invented or what it was used for. We do know, however, that they existed over 5,500 years ago in ancient Asia.

    The oldest known transport wheel was discovered in 2002 in Slovenia. It is over 5,100 years old. Evidence suggests that wheels for transport didn't become popular for a while, though. This could be because animals did a perfectly good job of carrying farming tools and humans around.

    But it could also be because of a difficult situation. While wheels need to roll on smooth surfaces, roads with smooth surfaces weren't going to be constructed until there was plenty of demand for them. Eventually, road surfaces did become smoother, but this difficult situation appeared again a few centuries later. There had been no important changes in wheel and vehicle design before the arrival of modem road design.

    In the mid-1700s, a Frenchman came up with a new design of road—a base layer (层) of large stones covered with a thin layer of smaller stones. A Scotsman improved on this design in the 1820s and a strong, lasting road surface became a reality. At around the same time, metal hubs (the central part of a wheel) came into being, followed by the pneumatic tyre (充气轮胎) in 1846. Alloy wheels were invented in 1967, sixty years after the appearance of tarmacked roads (柏油路). As wheel design took off, vehicles got faster and faster.

On an autumn afternoon, a remote sheep farm in southern Greenland is quiet. The silence is abruptly broken when dozens of sheep come thundering across the hills overlooking the farm. Walking after them are Lars Nielsen and his 37-year-old son Kunuk Nielsen.

The Nielsen family has owned and run the farm since 1972. Kunuk says the summers now are longer than when he was a child and that drought has become a problem. The fields are not so green as those in the old days. He has to buy hay (草料) from European countries.

The effects of a warming climate are obvious on the land. While he intends to struggle on, his older brother Pilu has chosen a different path.

Pilu, 40, lives in Qaqortoq in the south of Greenland -- a town of about 3,000 people. Ten years ago, he got his helicopter pilot's license and is now part owner of a small company called Sermeq Helicopters. It caters to construction and telecommunication workers and an increasing number of foreign tourists.

Pilu says he loves his family's sheep farm. But he saw that warming temperatures were making remote areas of Greenland more accessible and wanted to look for other opportunities. His company's most popular tours include a visit to Greenland's glaciers.

The warming temperatures are also affecting traditional ways of life, particularly hunting. The sea ice is changing; it's becoming less so that hunting on ice becomes more difficult. When there's no sea ice, it's difficult to use dog sledges (雪橇), and the whole culture around having dogs and dog sledges and doing traditional hunting on the ice is sort of diminishing.

Besides, many Greenlanders, like Pilu, are leaving the countryside for towns and the capital city Nuuk, where opportunities are greater. A report found that Nuuk's share of Greenland's population grew from 17.2% in 1977 to 29.2% in 2014. If there were enough houses in Nuuk, the share would even be bigger.

When it comes to helping students learn and mature, there are several ways to increase their well-being. Although your children may be succeeding in the classroom, there are a few things that you still can do.

Encouraging physical activity is the first thing you can do. More and more children do not participate in sports after school. It's important for you to encourage mobility with sports played after class. You should find sports equipment, basketball courts and play areas where kids can increase their well-being. {#blank#}1{#/blank#}

Secondly, you can provide proper nutrition for your children. It's important for your children to receive proper nutrition both inside and outside of the home. {#blank#}2{#/blank#}You'd better make it a point to provide enough nutrition for their proper development and growth.

{#blank#}3{#/blank#}Many parents fail to stop children from using smartphones and computers. There are some institutions that even encourage too much screen time as a way to teach children or keep them entertained. You should help the children remain excited without sitting in front of a screen throughout the day.

Last but not least, monitoring bullying(欺凌) is also an essential part. Bullying continues to remain a common problem in some schools, making it important that the environment that your children grow in holds a high standard.{#blank#}4{#/blank#}

It's important to examine the school life as a whole to determine what factors are missing. {#blank#}5{#/blank#}You may determine how well they adjust to the world around them and succeed in life.

A. You should provide kids with fresh food.

B. Besides, you'd better limit their screen time.

C. It will encourage children to focus on their study.

D. In addition, try your best to give them more freedom.

E. This will reduce the risk of health conditions that include obesity.

F. You can advise teachers to keep a practice of looking for bullying.

G. Parents play a significant role in children's growth and well-being.

A simple gesture can be formed into a child's memory so quickly that it will cause the child to give a false answer to a question accompanied by that gesture. A new finding suggests that parents, social workers, psychologists and lawyers should be careful with their hands as well as their words. 

Gestures can be as informative as speech, but hand gestures are so common that we rarely notice we're using them. 

While the recall of both adults and children are easy to react to suggestion, the memories of children are known to be particularly influenced, said lead researcher Sara Broaders of Northwestern University. Kids are used to looking to adults to tell events for them and can be misled even if not intentionally(故意地). 

Previous research, for example, has shown that detail-loaded questions often cause false answers; when asked, say "Did you drink juice at the picnic?", the child is likely to say "yes" even if no juice had been available. It is not that the child is consciously lying, but rather the detail is quickly formed into his or her memory. 

To avoid this problem, social workers have long been advised to ask children only open-ended questions, such as "What did you have at the picnic?" But an open-ended question paired with a gesture, briefly meaning a juice box, is treated like a detailed question. That is, children become likely to answer falsely. 

And it isn't just a few kids: 77% of children gave at least one piece of false information when a detail was suggested by an ordinary gesture. Gestures may also become more popular when talking with non-fluent language users, such as little kids, Broaders said as hand movements can impart meaning of unfamiliar words and phrases. "It certainly seems reasonable that adults would gesture more with children. "

In general, Broaders advises parents and other adults to "Try to be aware of your hands when questioning a child about an event. Otherwise, you might be getting answers that don't reflect what actually happened. "