China is a big country, and there is no simple answer to the question “When is the best time to visit China? ” There are two best times to visit China, depending on your preference.

    October

    Things to do: hike on the Great Wall, photography tour

    Places to visit: Beijing, Xi'an, Shanghai, Guilin, Jiuzhaigou, Chengdu

The best time to go to China is early autumn (October).

    Most of China has warm temperatures, and the summer rains have stopped (apart from around HongKong and Sanya) so it's pretty dry. The autumnn colours are also amazing. It is quiet at tourist attractions for most of the month, as the summer holiday travel crowds have gone. But try to avoid October 1st -7th, which is the Chinese National Day holiday, as attractions, transport and hotels are packed with Chinese tourists and prices go up a lot.

    Late Spring (April to May)

    Things to do: appreciate flowers, Li River cruise, ethnic festivals

    Places to visit: Beijing, Xi'an, Guilin, Huangshan, GuiZhou, Zhangjiajie

    The second-best time to travel to China is probably in April and May, when the flowers are in bloom and the temperatures are warming up. In late spring, temperatures across China are getting into the 20s (℃), except the extreme northwest and northeast. While the North of China is still dry, the summer rains have already begun in the South. This could actually improve the view in the form of mountain fog in mountainous areas like the Li River and the Yellow Mountains.

    Ethnic festivals in GuiZhou are concentrated in April and May, such as the Sisters' Meal Festival. If you are interested in Miao and Dong ethnic cultures, this is a good time to visit.

    Travel prices are average: cheaper than June to October, but more expensive than the lower season from November to March.

    A new collection of photos brings an unsuccessful Antarctic voyage back to life. Frank Hurley's pictures would be outstanding — undoubtedly first-rate photo-journalism — if they had been made last week. In fact, they were shot from 1914 through 1916, most of them after a disastrous ship wreck (海滩) by a cameraman who had no reasonable expectation of survival Many of the images were stored in an ice chest under freezing water, in the damaged wooden ship.

    The ship was the Endurance a small tight Norwegian-built three-master that was intended to take Sir Ermest Shackleton and a small crew of seamen and scientists, 27 men in all, to the southernmost shore of Antarctica's Weddell Sm. From that point Shackleton wanted to force a passage by dog sled across the continent. The journey was intended to achieve more than what Captain Robert Falcon Scott had done. Captain Scott had reached the South Pole early in 1912 but had died with his four companions on the march back.

    As writer Caroline Alexander makes clear in her forceful and well-researched story The Endurance、adventuring was then a thoroughly commercial effort Scott's last journey, completed as he lay in a tent dying of cold and hunger, caught the world's imagination, and a film made in his honor drew crowds Shackleton, a onetime British merchant-navy officer who had got to within 100 miles of the South Pole in 1908,started a business before his 1914 voyage to make money from movie and still photography. Frank Hurley，a confident and gifted Australian photographer who knew the Antarctic, was hired to make the images most of which have never before been published.

    The baby monkey is much more developed at birth than the human baby. Almost from the moment it is born, the baby monkey can move around and hold tightly to its mother. During the first few days of its life the baby will approach and hold onto almost any large, warm, and soft object in its environment, particularly if that object also gives it milk. After a week or m, however, the baby monkey begins to avoid newcomers and focuses its attentions on “mother" the real mother or the mother-substitute(母亲替代).

    During the first two weeks of its life warmth is perhaps the most important psychological(心理的)thing that a monkey mother has to give to its baby. The Harlows, a couple who are both psychologists, discovered this fact by offering baby monkeys a choice of two types of mother substitutes one covered with cloth 4nd one made of bare wire. If the two artificial mothers were both the same temperature, the little monkeys always preferred the cloth mother. However, if the wire model was heated, while the cloth model was cool, for the first two weeks after birth the baby monkeys picked the warm wire mother-substitutes as their fuvorites. Thereafter they switched and spent most of their time on the mw comfortable cloth mother.

    Why is cloth preferable to bare wire? Something that the Harlows called contact(触摸)comfort seems to be the answer, and a most powerful influence it is. Baby monkeys spend much of their time rubbing against their mothers' skins, putting themselves in as close contact with the parent as they can. Whenever the young animal is frightened, disturbed, or annoyed, it typically rushes to its mother and rubs itself against her body. Wire doesn't “rub" as well as does soft cloth. Prolonged(长时间的)“contact comfort" with a cloth mother appears to give the babies confidence and is much more rewarding to them than is either warmth or milk.

    According to the Harlows, the basic quality of baby's love for its mother is trust. If the baby is put into an unfamiliar playroom without its mother, the baby ignores the toys no nutter how interesting they might be. It screams in terror and curls up into a furry little ball. If its cloth mother it now introduced into the playroom, the baby rushed to it and holds onto it for dear life. After a few minutes of contact comfort, it obviously begins to feel more secure. it then climbs down from the mother-substitute and begins to explore the toys, but often rushes back for a deep embrace(拥抱)as if to make sure that its mother is still there and that all is well. Bit by bit its fears of the new environment are gone and it spends more and more time playing with the toys and less and less time holding onto its “mother.”

    What is the single most effective way to reduce greenhouse-gas emissions? Go vegetarian (素食)？ Replant the Amazon? Cycle to work? None of the above. The answer is: make air-conditioners better. On one calculation, replacing refrigerants (制冷剂) damaging the atmosphere would reduce total greenhouse gases equaling 90bn tonnes of CO₂ by 2050. Making the units more energy-efficient could double that. By contrast, if half the world's population gave up meat, it would save 66bn tonnes. Replanting two-thirds of tropical forests would save 61 bn tonnes. A one-third increase in global bicycle journeys, just 2.3bn tonnes.

    Air-conditioning is one of the world's great overlooked industries. Automobiles and air-conditioners were invented at roughly the same time, and both have had a huge impact on where people live and Work. Unlike cars, though， air-conditioners have drawn little criticism for their social impact, emissions or energy efficiency. Most hot countries do not have rules to govern their energy use. There is not even a common English word for “coolth” (the opposite of warmth).

    Yet air-conditioning has done more than most things to benefit humankind. Lee Kuan Yew, the first prime minister of Singapore, called it “perhaps one of the signal inventions of history”. It has transformed productivity in the tropics(热带地区)and helped turn southern China into the workshop of the World. In Europe, its spread has pushed down heat-related deaths to 10% since 2003, Men 70,000 people than usual, most of them elderly, died in a heatwave. For children, air-conditioned classrooms are associated with better grades at school.

    Environmentalists who call air-conditioning “a luxury we cannot afford” have half a point, however. In the next ten years, as many air-conditioners will be installed(安装)around the world as were put in between 1902(invention time)and 2005.Unless energy can be produced without carbon emissions, these extra machines will warm the world. At the moment, therefore, air-conditioners create a vicious cycle. The more the Earth warms, the more people need them. But the more there are, the warmer the world will be.

    Cutting the impact of cooling requires three things. First, air-conditioners must become much more efficient. The most energy-efficient models on the market today consume only about one-third as much electricity as average ones, Minimum energy-performance standards need to be raised raised, orintroduced in countries that lack them altogether, to push the average unit's performance closer to the standard of the best.

    Next, manufacturers should stop using damaging refrigerants. One type called hydrofluoro-carbons, is over 1,000 times worse than carbon dioxide when it comes to trapping heat in the atmosphere. An international agreement to knock out these pollutants will come into force in 2019.

    Last, more could be done to design offices, malls and even cities so they do not need as many air-conditioners in the first place. More buildings should be built with overhanging roofs or balconies for shade, or with natural ventilation (自然通风).Simply painting roofs white can help keep temperatures down. Providing indoor air-conditioned comfort need not come at the expense of an overheating world.

    Mobile technology has created new ways for all types of learning styles to help discover new information. If you want to teach yourself things, here are some apps that will help you.

    Coursera

    Perhaps one of the biggest advancements in the history of e﹣learning, Coursera has teamed up with top school like Duke, Stanford, and John Hopkins to bring you direct access to real college courses in psychology, computer science, business, and technology. Each course features pre﹣recorded videos, projects, and quizzes, just like you'd receive inside the classroom.

    Lumosity

    This app features three﹣day sessions that target many different areas of brain activity：memory, speed, problem solving, and thinking flexibility. Each day you can participate in a timed session to sharpen mental intelligence and keep track of your progress over time.

    Duolingo

    If you've ever wanted to learn a new language but didn't know where to start or couldn't afford expensive apps, you need to check out Duolingo. This app teaches more than a dozen languages by breaking up exercises into mini games. The developer of Duolingo claims that 34 hours of learning in this app equals a full term's worth of school.

    EarthViewer

    Ever wonder what Earth looked like a million years ago？There's no better way to know than to look for yourself. Earth Viewer takes you on a digital journey to see how the landscape（地貌） and face of the planet has developed over the past 4.5 billion years, and view climate changes, sea level adjustments, or the evolution of famous cities.

    Do you suppose Darwin, one of the greatest scientists of all time, really did foolish experiments? Or did he do experiments that were so simple and basic that other people just thought they were foolish?

    Sometimes, people think they already know the answer to a question or the solution to a problem. Sometimes, they really do know an answer or a solution, but without thinking they are important.

    Charles Darwin didn't settle for(满足于) just thinking he knew something. And, he believed all things could be important however simple they seemed to be.

    Suppose you drop sheets of paper that are of exactly the same size and shape. If you drop them at the same time in the same place, they will fall in the same way. Now make one of the sheets of paper into a tight little ball and let it drop along with the other sheets. What happens? You have done an experiment that is so simple that you might think it couldn't be worth anything.

    But this simple experiment is important. It explains part of our present-day understandings of physics, ideas that were worked out long ago by Galileo and Newton. And these understandings set aside some of ancient Greek physics.

    Scientists sometimes stop to look at very simple things and to think very hard about them. Even the simplest idea, which we might think is foolish, can shake the foundations of science.