Man has been to the moon. It has been the first step towards future exploration in space. When compared with the distances between Earth and the other planets, the distance between the Moon and Earth is very short indeed. Mars, the nearest planet to Earth is millions of miles away! Traveling to the planets will be man's next step. Such travels will be more challenging than the trip to the moon and certainly more exciting and dangerous. Recently, two American spaceships, Viking 1 and 2, landed on Mars trying to discover whether that planet has any life on it. So far the signs of life on Mars has neither been confirmed nor ruled out (排除). Russians have discovered that the surface of Venus is so hot that it is almost certain that there is no life there. Also the atmosphere of Venus is extremely dense and the pressure is nearly a hundred times greater than that of the Earth's atmosphere. Scientists believe man may find planets which have the same conditions as those we have on Earth, but man should realize Earth will be his only home for a long time and begin to love and care for it.

    Frigatebirds seagoing fliers with a 6-foot wingspan, can stay aloft(up in the air) for weeks at a time, a new study has found.

Since the frigatebird spends most of its life at sea, its habits outside of when it reproduces on land aren't well-known-until researchers started tracking them around the Indian Ocean. What the researchers discovered is that the bird's flying ability is unbelievable.

    Ornithologist(鸟类学家) Henri Weimerskirch put satellite tage(标签) on a couple of dozen frigatebirds. When the data started to come in, he could hardly believe how high the birds flew.

    "First, we found, 'Whoa, 1,500 meters. Excellent,' " says Weimerskirch, "And after 2,000, after 3,000, after 4,000 meters-OK, at this altitude they are in freezing conditions, especially surprising for a tropical bird."

"There is no other bird flying so high relative to the sea surface," he says. "It's the only bird that is known to intentionally enter into a cloud," Weimerskirch says. And not just any cloud—a soft, white cumulus cloud(积云). Over the ocean, these clouds tend to form in places where warm air rises from the sea surface. The birds take a ride on the current of rising air, all the way up to the top of the cloud.

    Frigatebirds have to find ways to stay aloft because they can't land on the water. Since their feathers aren't waterproof, the birds would drown in short order. They feed by harassing other birds in flight until they bring whatever fish they've swallowed back into their mouth and the frigatebird takes it.

So in between meals, frigatebirds fly higher... and higher.

    In one case, for two months-continuously aloft.

    One of the tagged birds flew 40 miles without a wing-flap. Several covered more than 300 miles a day on average, and flew continuously for weeks. They are blessed with an unusual body. No bird has a larger wing surface area compared with body weight.

    I began cycling in 2004 when I was a poor student. It was dangerous, sure, but cycling is the fastest, cheapest point-to-point form of transport in Melbourne. I own a car now, but that's just for transporting the baby or groceries.

    I hate driving. So it's been quite encouraging watching the growth in cyclist numbers over the past decade. It is estimated 10,000-plus cyclists enter the CBD (Central Business District) each day, taking pressure off public transport. But as more people take to cycling as a mode of transport, the number of cyclists seriously injured or killed keeps climbing. And that is a sign that our infrastructure (基础设施) is still not good enough.

    Melbourne was once a dream for cyclists-flat, long, wide roads, with plenty of paths along rivers. Now, cycling can be deadly, with roads dominated by cars. I have a friend who broke her back and was lucky to escape paralysis, and others with broken bones. In my time riding, I've been forced off the road by a truck, cut off by four-wheel drives, and told to get off the road.

    These things don't exactly happen to trams and buses, those other slowcoaches on Melbourne's roads. No—drivers reserve a particular savagery (残暴行为) for cyclists. And that's a sign of exactly one thing: inadequate infrastructure.

    We shouldn't need to be taught how to coexist in the same narrow space. Drivers and cyclists should be kept apart. The present debate over how to minimize “dooring” is a distraction.

    Dooring is not a legal problem. You cannot legislate (制定法律) it away. Designing bike paths so riders are channelled between moving cars and parked cars is deadly. All it takes is one daydreaming driver to fling open the door and you are gone. That's what happened to the young university student James Cross.

    This year, there are to be new anti-dooring lanes (车道) built on Glenferrie Road, Hawthorn, where Cross died in 2010. But these lanes are not safe. Cyclists must still pass between two rows of cars.

    Many animals recognize their food because they see it. So do humans. When you see an apple or apiece of chocolate you know that these are things you can eat. You can also use other senses when you choose your food. You may like it because it smells good or because it tastes good. You may dislike some types of food because they do not look, smell or taste very nice. Different animals use different senses to find and choose their food. A few animals depend on only one of their senses, while most animals use more than one sense.

    Although there are many different types of food, some animals spend their lives eating only one type. The giant panda eats only one particular type of bamboo. Other animals eat only one type of food even when given the choice. A land of white butterfly will stay on the leaves of a cabbage, even though there are plenty of other vegetables in the garden. However, most animals have a more varied diet. The bear eats fruits and fish. The fox eats small animals, birds and fruits. The diet of these animals will be different depending on the season.

    Humans have a very varied diet. We often eat food because we like it and not because it is good for us. In countries such as France and Britain, people eat foods with too much sugar. This makes them overweight, which is bad for their health. Eating too much red meat and animal products, such as butter, can also be bad for the health Choosing the right food, therefore, has become an area of study in modern life.

    Last week, Vodafone started a test of the UK's first full 5G service, available for use by businesses in Salford. It is part of its plan to trial the technology in seven UK cities. But what can we expect from the next generation of mobile technology?

    One thing we will see in the preparation for the test is lots of tricks with the new tech. Earlier this year, operators paid almost £ 1.4 billion for the 5G wavelengths, and to compensate for that cash, they will need to catch the eye of consumers. In September, Vodafone used its bit of the range to display the UK's first hologram (全息) call. The Manchester City captain Steph Houghton appeared as a hologram in Newbury. It isn't all holograms, however: 5G will offer faster internet access, with Ofcom (英国通讯管理局) suggesting that video that takes a minute to download on 4G will be available in just a second.

    The wider application is to support connected equipment on the "internet of things" -not just the internet-enabled fridge that can reorder your milk for you, but the network that will enable driverless cars and delivery drones (无人机) to communicate with each other.

    Prof William Webb has warned that the technology could be a case of the emperor's new clothes. Much of the speed increase, he claims, could have been achieved by putting more money in the 4G network, rather than a new technology. Other different voices have suggested that a focus on rolling out wider rural broadband access and addressing current network coverage would be more beneficial to the UK as a whole.

    Obviously, 5G will also bring a cost to consumers. It requires a handset for both 5G and 4G, and the first 5G-enabled smart phones are expected in the coming year. With the slow pace of network rollout so far, it is likely that consumers will end up upgrading to a new 5 G phone well before 5 G becomes widely available in the next couple of years.

    Vacation is a time for refreshment. In work, we are often called to think. Sometimes, it's good to give our brains a rest. Without a break, we may not be able to perform up to our potential. This can be a problem, not only for the employee, but for the employer as well.

    "The main benefit of vacation is for the worker to come back energized," says Weaver. "If they haven't had a break, then they're not coming back with new energy. They haven't had a chance to step back and get perspective（远景）, and come back with renewed enthusiasm."

    Long working hours without a break, insecurity about one's job, and other work-related worries can lead to burnout and stress. Humans can usually adapt to pressure, but not for a limitless amount of time.

    "It is a problem of relating good workers and having them loyal to the firm while they're there," says David Maume, PhD, professor of sociology at the University of Cincinnati. He says burnout can also affect employees' productivity, creativity, and effectiveness.

    In addition, high levels of stress may lead to depression, which can hit both the employer and employee's pocketbook. Even people who manage to remain productive at work can have problems. If they're always at work, then they're not with their family and friends. If they're working while on vacation, for the time that they're on the job, they're not really present.

    An unbalanced emphasis on work can strain family and social life. When you come up for air, you may see that you're alone, or that your relationships have gone on without you.