For incoming freshmen at western Connecticut's suburban Brookfield High School, lifting a backpack weighed down with textbooks is about to give way to tapping out notes and touching electronic pages on an iPad. A few hours away, every student at Burlington High School near Boston will also start the year with new school-issued ipads, each loaded with electronic textbooks and other online resources in place of traditional texts. Apple officials say they know of more than 600 districts that have launched what are called " one-to-one " programs.

    At Burlington High in suburban Boston, Principal Patrick Larkin says the $500 ipads is better than textbooks in the long term, though he said the school will still use traditional texts in some courses if suitable electronic programs aren't yet available. Larkin said of textbooks, " but they're pretty much outdated the minute they're printed and certainly by the time they're delivered".

    But some experts warn that the districts need to ensure they can support the wireless infrastructure (设施 ), repairs and other costs that accompany a switch to such a tech-heavy approach. Mark Warschauer, an education and informatics(信息学)  professor said,  "I think people will like it.I really don't know anybody in high school that wouldn't want to get an iPad," he said. "We're always using technology at home, then when you're at school it's textbooks. So it's a good way to put all of that together." Districts are varied in their policies on how they police students' use.

    And the nation's textbook publishing industry, accounting for $ 5.5 billion in yearly sales to secondary schools, is taking notice of the trend with its own shift in a competitive race toward developing curriculum specifically for ipads.Jay Dickey, executive director of the Association of American Publishers'schools division, said all of the major textbook publishers are moving toward electronic offerings, but at least in the short term, traditional bound textbooks are here to stay. "I think one of the real key questions that will be answered over the next several years is what sort of things work best in print for students and what sort of things work best digitally."

    On February 6, Space X, a private US aerospace company owned by Elon Musk, has successfully launched its new Falcon Heavy spacecraft, making it the world's most powerful rocket.

    Falcon Heavy is the largest rocket since the retirement of NASA's Saturn V, which was used for the Moon missions in the 1970s. “Falcon Heavy can launch about 64 tonnes into low Earth orbit-that's almost three times more than the current running biggest launch vehicle, Delta IV Heavy, ”Imperial College astrophysicist David Clements told AI Jazeera. According to Space X, Falcon Heavy can lift into orbit a mass greater than a 737 jet loaded with passengers, crew, luggage and fuel.

    The rocket was designed with the idea of earning humans into space and opening the possibility of flying missions with people to the Moon and even Mars. For its first voyage, it carried Musk's $ 100,000 cherry-red Tesla sports car and a fake space-suited human model fixed in the driver's seat. Musk joked that “it may be discovered by some future alien race”.

    Falcon Heavy went into space on its last flight on February 6. The launch took place at NASA's Cape Canaveral Air Force Station and Kennedy Space Center in the US state of Florida, the spot also used for the Apollo 11 Moon mission and several space shuttle launches. It was delayed by several hours because of high winds in the upper atmosphere. Minutes after take-off, the two outer boosters (助推器) landed at the nearby Cape Canaveral Air Force Station.

    Space X announced plans to eventually use Falcon Heavy to launch two paying space tourists on a trip around the Moon. However, Musk said he will probably reserve that mission for another launch system, the BFR. Recently, Space X scheduled to launch a Falcon 9 rocket for NASA's TESS mission on March 20, 2018. It is reported that Space X is scheduled to complete 30 independent launch missions in 2018, at least half of which will use Falcon 9.

    Andrew Ritchie, inventor of the Brompton folding bicycle, once said that perfect portable bike would be "like a magic carpet... You could fold it up and put it into your pocket or handbag". Then he paused: "But you'll always be limited by the size of the wheels. And so far no one has invented a folding wheel."

It was a rare — indeed unique — occasion when I was able to put Ritchie right. A 19th-century inventor, William Henry James Grout, did in fact design a folding wheel. His bike, predictably named the Grout Portable, had a frame that was divided into two and a larger wheel that could be separated into four pieces. All the bits fitted into Grout's Wonderful Bag, a leather case.

    Grout's aim: to solve the problems of carrying a bike on a train. Now doesn't that sound familiar? Grout intended to find a way of making a bike small enough for train travel: his bike was a huge beast. And importantly, the design of early bicycles gave him an advantage: in Grout's day, tyres were solid, which made the business of dividing a wheel into four separate parts relatively simple. You couldn't do the same with a wheel fitted with a one-piece inflated(充气的) tyre.

    So, in a 21st-century environment, is the idea of the folding wheel dead? It is not. A British design engineer, Duncan Fitzsimons , has developed a wheel that can be folded into something like a slender ellipse(椭圆). From beginning to end, the tyre remains inflated.

    Will the young Fitzsimons's folding wheel make it into production? I have no idea. But his inventiveness shows two things. First, people have been saying for more than a century that bike design has reached its limit, except for gradual advances. It's as silly a concept now as it was 100 years ago: there's plenty still to go for. Second, it is in the field of folding bikes that we are seeing the most interesting inventions. You can buy a folding bike for less than £1,000 that can be knocked down so small that can be carried on a plane ——minus wheels, of course ——as hand baggage.

    Folding wheels would make all manner of things possible. Have we yet got the magic carpet of Andrew Ritchie's imagination? No. But it's progress.

We are what we eat. That is an old expression, but one worth knowing. A recent look at diets around the world shows that people who eat healthy food—and not too much of it—live longer. But which areas of the world have the best diets？Researchers found that foods in some of the healthiest diets—Mediterranean, New Nordic, Japanese and French—may be very different, but they are all heavy on local, seasonal and limit processed foods, which are high in vegetables and seafood and low in red meat.

Mediterranean diet contains lots of fruits, vegetables, whole grains, nuts and olive oil. The diet has proper amounts of fish and poultry (禽肉). Red meat and foods high in sugar and salt are not big parts of this diet.

New Nordic diet has whole grains like oats and rye, vegetables such as carrots, broccoli and eggs, seafood, fruits, oil, low­fat milk and cheese. Very sugary desserts are not common in this diet.

Japanese people are some of the longest­living people on the planet, with women up to 87 years old and men up to 80. The Japanese diet is the reason for such lengths of life. The diet has many foods that are low in calories and high in nutrients. Japanese people eat a lot of seaweed, tofu, rice, vegetables and fish. The tradition there is to stop eating when your stomach feels 80 percent full.

However, French people eat fatty foods but do not get fat. And they live a long time. This phenomenon is called the "French Paradox". The reason why the French eat fatty foods without getting fat may be simple. They eat less. Serving sizes in French restaurants and in products sold in stores are smaller than those in most countries. And generally speaking, most French people do not snack. This means they do not eat food between meals.

It is amazing how many of the things in science fiction and movies have become reality.For instance,in the movie Star Trek,the workers could go to a replicator(复制器) and order food,drinks or anything they could program into the computer.Before long,the item would appear.This is possible today,in a way,with technology we have had for years.

Several manufacturers(制造商) have created 3D printers.One company,MakerBot,has created a printer that the average person can afford.It is called The Replicator.You can download a lot of design software from the Internet for use with The Replicator.In the near future,rather than going to a store to buy what you need,you may be able to download what you want from the Internet and print it out at home.

The process was first used with music.At the very beginning,music was recorded onto plastic disks with etching(蚀刻法).Music can now be copied without a physical product.____ Rather than having to buy a physical book or magazine,you can now download them from the Internet in digital form.

This technology is already used in engineering and architecture.Melissa Shoes,a Brazilian foot wear company,is using this technology to create shoes.Rather than having to go through the current process of product design and development,the company is able to design and print shoes for display to see how well they will sell before having lots of them made.

For Adam Johnson, a potter from Brighton, the interest stirs (萌动) each spring. "It grabs a hold of me," he said. "I just get the desire to dig." Together with his shovel (铲), he is part of a larger movement. Around the world people are discovering the joys of an ancient practice: the digging of holes. TikTok videos of people digging purely for fun have been viewed millions of times. Instagram accounts devoted to the pastime have many followings.

Charlie Mone, a student at St Andrews University, was changed while digging on the beach in Gran Canaria last year. When he returned home, he founded the university's first hole-digging society. "I didn't think it would go anywhere," he said. Dozens of diggers regularly attend its events on East Sands Beach on the east coast of Scotland and the society's Facebook page has more than 300 followers.

Mone believes that that much of the appeal lies in the friendship working on a shared project in the sea air. "It's struck a chord (共鸣) with people," he said. "There's something therapeutic to just switching your brain off and digging a hole." At the end of each 1 session, the holes are filled in to prevent accidents.

Back in Brighton, Johnson, 38, is more of a lonely digger. "I have often started digging without an actual plan," he said. "Once I took out an unruly bramble (荆棘) and found some rock so I dug that out, then carried on a bit until I was in a good general digging rhythm. A few hours later my partner asked if I was coming in for dinner-the bramble had come out at breakfast and I found myself in a six-foot hole. The hole would become a sunken hot tub, but the digging would have been worthwhile anyway, he suggests. "There's something basic about it. And you find all kinds of buried treasure from people who had the garden before you. There's something magical about digging."