Four to one to the computer. That was the score. AlphaGo, a program developed by Google’s London-     1     artificial intelligence(AI)team DeepMind, has just beaten a human at a really     2     game. The field of honour is a Go(围棋)board in Seoul, South Korea. Lee Sedol, a South Korean, is a world Go champion and is honoured the game’s most outstanding player. But he was defeated by AlphaGo.

The contest has     3     tens of thousands of online spectators who have followed the matches live on the Internet. Videos of the competition have received more than four million views since the contest began on 9 March. The five-game contest took a week in all. At a pre-match press conference, Lee said he was confident he would win five to nil(零分)or, at least, four to one,     4     he defeated AlphaGo only once in the fourth game.

Go, which     5     in China thousands of years ago, is played on a board of 361 crosses with black and white stones(棋子). The board’s design means the number of possible moves is greater than the number of atoms in the observable     6    . Go is said to be the only game that truly     7     the left and right sides of the brain. According to Demis Hassabis, the     8     founder of DeepMind, Go poses a more difficult programming challenge than chess. AlphaGo’s success marked the most significant milestone ever in AI.

Yet AlphaGo is only going to get smarter     9     it gathers more data from which it learns. Asked whether there was a(n)     10     to its abilities, Hassabis said he did not know. “If there is, we haven’t found it yet.”

Shopping in the States in always a pleasant experience. There are different types of shops that cater to your particular needs.

Some of big chain supermarkets,     1     with automatic checkout lanes, have brought real convenience to the customers. Most packaged goods have barcodes (条形码) and you just     2     them on the scanning machine when you check out. Some items, such as vegetables and fruits, do not have barcodes on them. You need to input their     3     numbers, which can be found on the list glued to the scanning machines. These automatic checkout lanes help the stores reduce their labor cost and increase their     4    . Many foreign visitors will be greatly     5     the first time they use the automatic checkout lane.

According to the policy in some supermarket, if the customer discovers a scanning problem, he will get the product for free as a(n)     6     for him or a penalty for the supermarket. In most cases, customers from other countries can’t help     7     at the honesty of the clerk.

A shopping mall in the States is composed of many individual specialty shops and nationwide chain stores. No matter what you buy, if you find some problems with them or     8     do not like them any longer, you can return them within 30 days. You won’t be     9     at the customer service counter as long as you have your receipt. Of course there are some people who might take advantage of this return policy, especially when they need something for momentary use.

Even with a wetsuit, a cold water dive can be a bone-chilling experience. In Arctic waters, divers     1    last only an hour, and even that short time can lead to numb, painful extremities.

But, by improving on a(n)    2    already used in nature, researchers say that they’ve turned regular wetsuits into what they call “artificial blubber (人造脂肪),” greatly increasing their    3    with just a simple treatment.

Currently the only cold-water    4     to wetsuits are dry suits and warm-water suits, which respectively keep a layer of air or warm water between the suit and the skin. “But those suits are vulnerable to being ripped, and if they do, they fail catastrophically (灾难性地), and you have to come out of the cold water immediately,” said study co-senior author Michael Strano, a chemical engineer at MIT.

MIT scientists were invited by the U.S. Navy and the SEALs to look for longer-lasting protection in icy waters. “As the Arctic opens up because of climate change, the Navy is going to be doing more work in Arctic water,” Strano said. The researchers analyzed different     5    used by various animals in arctic conditions. They found three strategies. One    6    air pockets trapped in fur or feathers, as seen with otters and penguins.     Another is through internally generated heat, as with some animals and fish, including great white sharks. The last is a layer of the material that greatly    7    heat loss from the body, as with seal and whale blubber.

The scientists ultimately developed a way to upgrade any conventional wetsuit into a blubber-like insulating suit. “We’ve made the lowest thermal conductivity garment on record,” Strano said.

Gas Matters Standard wetsuits are made of neoprene, a synthetic rubber made into a kind of foam.

    8    within the structure of neoprene are tiny pockets of air that take up more than two-thirds of the material’s volume and    9    for half of the heat that gets transferred through it.

The new method simply involves placing a wetsuit inside a pressure tank no bigger than a beer keg filled with a heavy inert gas such as xenon or krypton — which transfer far less heat than air does — for about a day. This heavy gas replaces the normal air within the neoprene, greatly enhancing its    10    of heat insulation.

This new strategy raises the amount of time divers can survive in water colder than 10 degrees Celsius from less than one hour to up to three hours. The enhancement to the suit can last for roughly 20 hours, much longer than anyone would spend on a dive, the researchers said. The researchers are now looking for volunteers to test the inert gas-filled wetsuits.