3 . A few months ago, a friend gifted me a robot sweeper that’s programmed to move around a room and clean as it goes.

When the box arrived, I was afraid the device would detect me and suck up (汲取) data along with the dog hair and dust. But the instructions were easy, and I finally decided not to care.

I powered up the sweeper, watched it leave its docking station to work, and quickly fell in love with my newly shiny floors. I kept shooting its working videos. “I think you’re giving more attention to it than to us,” joked my son.

One day, I returned home and discovered that our front door had blown open and the robot rolled into the yard, trying to clean the flower beds. Even when its brushes were blocked with leaves, bugs and mud, its little wheels bravely kept turning.

The robot acted properly as it was programmed to clean “dirty” things. In a kitchen, dirt can be garden debris (碎片) such as leaves and mud. In a garden, this kind of dirt does not need to be removed. The context is important. The problem for robots is that reading this context is difficult.

This accident inspired me to think more about AI (artificial intelligence). As far as I am concerned, AI is simply well trained and reproduces what it has learned. And it is undeniable that robots are increasingly being given powerful intelligence. Some experts even predict that we will soon see not only AI-enabled robots designed to solve problems according to their instructions, but also those with the ability to judge how they should respond when they are in a different setting.

Maybe this will happen in the near future.

4 . If you spend more than a couple of days in the country of Georgia, you are very likely to be invited to a Georgian feast even by complete strangers. The multi-hour, multi-course feast is one of the most important events in Georgian culture.

A popular Georgian story shows the importance of the feast in Georgian culture. When God created the world, He held a meeting to give the different regions of the world to different cultures. But the Georgians arrived late at the meeting. After they apologized and explained that they’d been holding a feast with a stranger the night before and slept later than they’d meant to, God was so touched and impressed by their honesty that He gave the Georgians the best land of all: the part of earth He was saving for himself.

In order to survive the feasts without offending (冒犯) the hosts, it’s important for you to know a few things about it in advance.

A Georgian feast will likely have a seemingly unlimited number of dishes. So avoid fully cleaning your plate unless you want more servings. Don’t fill up on khachapuri-Georgian cheese bread. There are numerous regional varieties of cheese bread, but khachapuri is the most delicious of all. The cheese bread is usually a heavy lunch on its own, but at feasts it’s often considered a side dish or an appetent. Don’t make the mistake of having more than a few bites—only to discover that the main meal is still coming.

When you drink, follow the lead of the toastmaster, who presents a scries of toasts throughout the evening. Traditionally, drinkers would dry their glass (or, if keeping with tradition, drain their deer’s horn) with every toast. This isn’t always done now. Just remember the important rule: say “cheers” after every toast.

Consider bringing a small gift, such as sweets or flowers, as a gesture of thanks. Avoid bringing more fond, however, which might imply that you don’t think there will be enough on offer.

Xu Xiake was born in 1587.     1     (he) parents were rich landowners. Yet he gave up a     2     (comfort) life, and decided to explore the mountains and rivers on foot.

China has more famous explorers. There was: Zhang Qian, who traveled into Central Asia during the second century BC, opening a trade road that became     3     is known as the Silk Road. Or Zheng He, the sailor who in the 15th century sailed as far away as Africa. Yet these explorations     4     (support) by governments. Xu was totally different.

“On the surface, Xu’s travels can neither be classified as great affairs of state     5     great adventures that changed the course of history,” writes cultural historian Cheng Pei-kai. “Xu travelled to satisfy his own     6     (curious).”

Scholar Julian Ward agrees, describing the lonely Chinese wanderer like the Middle Kingdom’s version of John Muir: “Deep in love with nature and eager to find freedom     7     worldly concerns, Xu was a man addicted to     8     (see) and describing the landscape.”

“The few coins     9     (slip) from a hole in my pocket while I was climbing a mountain in Yunnan. When I finally managed to the town, I sold all my clothes, bought myself a bottle of wine and a good dinner     10     (celebrate) my survival,” the dreamy explorer wrote in his diaries, which mix details of geology, geography and botany with such personal travel experiences.

9 . Imagine a school where students are taught by the best teachers in every subject, regardless of locations. Imagine a school where children can go on safe field trips to the Amazon rainforest or Everest base camp. Well, such schools are already being built: in virtual reality(VR).

Last month, Optima Academy Online (OAO) was launched in Florida and started to deliver courses for elementary, middle and high schools and 170 full-time students from all over the state signed up. They used VR headsets for about three hours a day for formal lessons and then do course work independently with digital check-ins.

It is worth watching how such educational experiments develop. Used properly, the VR technology can help students to access learning resources and be connected with fellow students and teachers all over the world. But if employed poorly, it will have the opposite effect and turn a digital inequality into an educational one.

There is growing evidence to suggest that it is happening. In Mexico, according to a survey, only 24% of 15-year-old students in poor schools have access to home computers for schoolwork compared with 87% in rich ones. As reported in another study, some students in northern England have been forced to travel around on the Greater Manchester train network or camp out around McDonald’s to access free WiFi because they cannot do their schoolwork at home.

“VR technologies will be widely used in education. The only questions are: for what purpose and at what speed?” says Beeban Kidron, a member of the UK’s Digital Futures Commission. “The trouble is that they are too often seen as a shiny new toy that will solve all problems and save money rather than being viewed as a means to enrich learning.”

The inescapable truth is that there is nothing that can replace teachers educating students in safe schools—ideally, with access to well-designed technological platforms. Leaving children in their bedrooms with just VR headsets and no physical social interaction with other kids will fill-many of them—and their parents—with horror.

10 . If you decide to see the northern lights, consider heading to Canada, where they fill the sky 300 days a year in certain regions.

Yukon

With its sweeping landscapes and dramatic mountain views, Yukon is an outdoor lover’s dreamland. Take advantage of the brief window between the end of summer and first snowfall in autumn to combine outdoor activities like boating along the storied Yukon River with northern light watching.

Churchill

Home to wolves, foxes, whales, moose and snowy owls, Churchill is well known for its arctic wildlife. It also sees an average of 300 nights of northern light activity every year. With over a week in the wild, there’s a good chance you’ll spot the lights.

Nunavik

Nunavik is Quebec’s northernmost region and one of four areas in Canada. It is home to the country’s Inuit people. By day, travelers canoe or snowmobile to Vieux Fort-Chimo, a 19th-century fur trading post; hear elders tell stories of a nomadic (游牧的) way of life; and listen to traditional throat singing, or katadjak — all led by an Inuit guide. Under inky skies, the guide offers Inuit insights into the meaning of the light.

Jasper

Located in the Rocky Mountains, Jasper is home to the world’s second-largest dark sky preserve, making it one of the best — and most convenient — places to catch northern lights throughout the year.

An especially great time to visit is during the annual Jasper Dark Sky Festival in October when experienced photographers from around the world host workshops to share their best tips and astronomers explain how to interpret space weather data to determine optimal viewing time.