For thousands of years comets have been a mystery to man. They travel across the sky very fast and have a bright “tail” of burning gas. The comet Tempel 1 has an orbit（轨道） far outside the orbit of the furthest planet in our solar system, Pluto. It has been there for 4.6 billion years, 133 million kilometers from Earth. Last week a little American spacecraft crashed into Tempel 1. The spacecraft had a camera and it took a photograph of the comet every minute before it finally crashed into its surface.

    The space mission to Tempel 1 cost $335 million and was called Deep Impact. The spacecraft was travelling at 37,000 kilometers per hour when it hit the comet and the crash completely destroyed the spacecraft. But before it hit the comet, the spacecraft took some amazing photographs. The last one was a close-up picture which the spacecraft took just 3 seconds before it crashed into the comet.

    “Right now we have lost one spacecraft,” said a delighted NASA engineer. Deep Impact was like a American Independence Day fireworks display. It took many years to plan and ended in an enormous explosion. 

    The spacecraft which crashed into the comet was made of copper and was the size of a washing machine. It was dropped from a mothership into the path of the comet and the mothership then photographed the cloud of ice, dust and organic chemicals that rose from the surface of the comet after the crash.

    The crash completely destroyed the spacecraft but nothing really happened to the comet: experts believe that the crash slowed the comet down by no more than 1/10,000 of a millimeter a second.The aim of the mission was to study for the first time the interior of a comet.

    The mothership was 480 km from the explosion and observed the crash and the explosion with instruments for 800 seconds. Seven satellites, including the Hubble space telescope, watched the moment of drama, and over the next day and night about 50 telescopes on Earth were watching the distant comet.

    The Thanksgiving Day ,the fourth Thursday in November, is coming in America. But do you know something about the annual(每年的)Macy's Thanksgiving Parade(游行) in New York?

    There are thousands of bystanders(看热闹的人)and millions of television viewers. The Parade is as traditional as turkey. The year 2016 was the 90th year of Macy's parade. It featured 15 huge balloons in the shape of cartoon and pop culture characters, 1,200 dancers and cheerleaders, 900 clowns(小丑),10 marching bands and nearly 9,000 workers, almost all of whom were volunteers.

    The floats(彩车)and balloons have been getting larger ,more colorful and more surprising since Macy's immigrant (移民的) workers organized the first Thanksgiving Day Parade.

    In 2016, school children were invited to the Macy's parade studios(画室) outside New York City, for a first look at several just completed floats.

    Bella was excited to be there. “I think it's great because I get to see all of these floats before anyone else does in the parade,” said Bella.

    John Piper is the president of Macy's Studio. He said his work was fun all the time. “It's a lot of work. All year long, the artists at Macy's Studio all build these floats. We create them from scratch(涂抹). I have the finest carpenters(木匠), metal workers, painters all cooperating(合作) together,” said Piper.

    The floats were supposed to advertise for commercial sponsors(赞助商) for the start of the Christmas season. But Amy Kule, the event producer said, “ And the floats are used to keep the beauty and the majesty(庄严)of the parade. A Thanksgiving parade is always about giving back and entertaining(娱乐). But most importantly, it's about leaving it for the next generation.”

    The Intelligent Transport team at Newcastle University have turned an electric car into a mobile laboratory named “DriveLAB” in order to understand the challenges faced by older drivers and to discover where the key stress points are.

    Research shows that giving up driving is one of the key reasons for a fall in health and well-being among older people, leading to them becoming more isolated(隔绝) and inactive.

    Led by Professor Phil Blythe, the Newcastle team are developing in-vehicle technologies for older drivers which they hope could help them to continue driving into later life.

    These include custom-made navigation(导航) tools, night vision systems and intelligent speed adaptations. Phil Blythe explains: “For many older people, particularly those living alone or in the country, driving is important for preserving their independence, giving them the freedom to get out and about without having to rely on others.”

    “But we all have to accept that as we get older our reactions slow down and this often results in people avoiding any potentially challenging driving conditions and losing confidence in their driving skills. The result is that people stop driving before they really need to.”

    Dr Amy Guo, the leading researcher on the older driver study, explains, “The DriveLAB is helping us to understand what the key points and difficulties are for older drivers and how we might use technology to address these problems.

    “For example, most of us would expect older drivers always go slower than everyone else but surprisingly, we found that in 30mph zones they struggled to keep at a constant speed and so were more likely to break the speed limit and be at risk of getting fined. We're looking at the benefits of systems which control their speed as a way of preventing that.

    “We hope that our work will help with technological solutions(解决方案) to ensure that older drivers stay safer behind the wheel.”

    David Lindenmayer of the Australian National University College of Science in Canberra says that older trees play important roles in maintaining landscapes and ecosystems.

    David studies conservation, landscape, ecology and biodiversity at the Australian National University College of Science in Canberra. “Lots of people recognize that as humans get older they tend to have less and less children while trees do it the other way around. What really happens is that the older some of these really big old trees get, the more seeds they produce and the more germinant（萌芽的）they're likely to be. So it's actually the polar opposite of what we see with humans and most other animals, so really quite extraordinary. “On January 26th he spoke to Scientific American Editor in Chief Mariette DiChristina when they were both at the World Economic Forum in Davos.

    In actually it's quite a worrying situation, because in plenty of forests and woodland and other ecosystems around the world, populations of large old trees are declining very quickly. And this matters because a lot of biodiversity, a lot of carbon, a lot of key ecosystem processes are associated with those really big, old trees.

    We can make sure we grow more forests, that we protect the big trees we have now, and that we don't do things that really put a lot of pressure on those trees. We should not be cutting down really big old trees anymore.

    Some students prefer a part-time job after class to earn some money and improve themselves. Here are some good companies:

    IN-N-Out Burger

    It is the best hamburger shop in the west of America. Regarded as one of the best employers, it offers flexible hours and the highest part-time salaries(薪水). Above all, the company treats its employees the way they would like to be treated: like family. However, there is no discount offered to its employees.

    Position: selling assistant (experience required)

    Website: www.in-n-out.cm

    Starbucks Coffee

    Starbucks has been at the forefront(前沿) of the United States' coffee revolution. Working hours are flexible. Fit twenty hours of work into your week. There is also a 30% discount and a free pound of coffee or box of tea every week.

    Position: assistant coffee taster(experience required)

    Website: www.Starbucks.Com

    Whole Foods Market

    Whole Foods Market is the world's largest natural and organic food selling company. With its focus on organic ingredients, Whole Foods Market is all about health. Working hours are flexible. Benefits include paid-time off and a 20% discount so you can eat like a king or at least like a top chef in training. There are also training courses on health and food every week.

    Position: secretary

    Website:www.wholefoodsmarket.com.

    Lands' End

    Lands' End is a Wisconsin-based clothes store that focuses on casual comfort and warmth for the great outdoors. Employees(even part-time employees) have the chance to go to a company-owned entertainment centre and get a 25% discount on theme parks and movies, and an invitation to the yearly company picnic. Besides, for part-time employees, working hours are flexible and they can come to work anytime they like as long as they work for 4 hours a day.

    Position: salesperson

    Website: www. landsend.com

    It was a quiet village in which there was a military camp(军营). It was far from the towns and cities and there were some high mountains around. Of course it was a good place for training the new soldiers. But it was difficult for the young men to go outside. Mr White, an officer of forty, was strict with them and he hardly let them leave the camp.

    Once Mr White was ill in bed. He couldn't work and a young officer, Mr Hunt, began to train the new soldiers instead of him. He knew the young men well and let nine soldiers go to the nearest town to have a holiday. But night fell and none came back to the camp. He was worried about it and stood at the gate. It was five to twelve when Mr Hunt decided to go to the town and see what was happening to the young men. He started the car quickly and set off. At that moment the nine soldiers came back. It seemed they drank wine. Of course they found the officer was angry.

    "I'm sorry, sir," said the first soldier. "I left the town on time. But something was wrong with my bus on my way here. I had to buy a horse and made it run fast. Bad luck! It died and I had to run back."

    And the other seven soldiers said they were late for the same reasons. It was the last soldier's turn. He said, "I'm sorry, sir. I got on a bus on time, but……"

    Having heard this, the officer became even angrier and stopped him at once. He called out, "If you say something was wrong with your bus, I'll punish you at once!"

    "No, no, sir," said the young man. "My bus was all right, but the dead horses were in its way!"