1 . Laughter comes in many forms, from a polite and quiet laugh to a great hearty laugh. Scientists are now developing an AI system to recreate different laughs in proper social contexts. The team behind the laughing robot Erica said that the system could improve natural conversations between people and an AI robot. “We think that one of the important functions of conversational AI is empathy(共情),” said Dr Koji Inoue, the lead author of the research. “So we decided that one way a robot can empathize with its users is to share their laughter.”

The team have set out to teach their AI system the art of conversational laughter. They gathered training data from more than 80 daily dialogues between male subjects and the robot that was initially operated by four actresses remotely. The dialogue data was grouped into social laughs (where polite or embarrassed laughter isn’t involved) and laughter of joy. Based on the audio files, the algorithm(算法) learned the basic characteristics of social laughs, which tend to be softer, and merry laughs, with the aim of mirroring these inappropriate situations.

“Our biggest obstructor in the work was identifying the actual cases of shared laughter because as you know, most laughter is actually not shared at all,” said Inoue. “We had to carefully decide exactly which laughs we could use for our analysis and we couldn’t just assume that any laugh can be responded to. It was really not easy work.” The team said laughter could help create robots with their own distinct character although it could take more than 20 years before it would be possible to have a casual chat with a robot like we would with a friend.

“One of the things we’d keep in mind is that a laughing robot or algorithm will never be able to understand you or the meaning of laughter,” points out Prof. Sandra Wachter of the Oxford Internet Institute. “But with their development, they might get very good at tricking you into believing they understand what’s going on.”

2 . Every fast-food employee knows that the drive-through window is the worst position. It was a freezing afternoon. Drivers _________ to stand outside in the cold and scream their orders into a speaker box. In such cases, most customers tend to take out their _________ on the employees. This woman was a(n) _________.

“I`ll get the next car’s order as well,” she said as she came up to the window to pay. She _________ outside, gathering snowflakes on her hair and eyelashes. “You can’t take their drinks,” I said, confused and tired. The lady laughed, her cheeks turning red with _________. “No, but I’ll buy them,” she said. “_________ it forward and all that.”

Completely shocked, I _________ her as requested, and when the next customer arrived at the window I _________ what had just happened. His facial expression changed like a chain of photographs on a slideshow—first _________ to be out in the cold, then surprised at the random act of ____________ and finally, delighted by his luck. “I suppose I’ll pay for the next order then,” he replied, nodding and waving at the ____________ driver behind him. He handed over the cash and received his pre-paid ____________.

The trend ____________ throughout the entire rush hour. Customers stood at my window emptying a handful of change to buy coffee for a complete ____________. Actually, it only takes one customer, one person, to change the entire flow of traffic. It only takes one moment, one smile, to ____________ even the coldest days.

3 . Life is full of uncertainties, and every activity we do carries some level of ________ . Some activities, like snowboarding (单板滑雪运动), often have a higher possibility of injury. Ian Steger ________ this firsthand when he had a serious snowboarding accident but he was so ________ that Francis Zuber passed by.

In March, Ian and a group of friends went on a snowboarding trip in Washington State. During their ________ , things took a dangerous turn. While moving through the trees, Ian fell backward and crashed into one, finding himself ________ in a deep hole of snow.

Ian explained the ________ , “When we entered the trees, they were so ________ together that we each had to find our own paths. Unluckily, the path I ________ led me straight into a big tree well.” Fearing the worst, Ian thought he was facing his   ________ moments. However, Francis Zuber, a skier, happened to pass by.

Francis saw a flash of red in the corner of his eye. He ________ a snowboard sticking out from the snow, which was ________ considering how far they were from any populated areas. Worried, Francis called out to Ian but didn’t receive any ________

Without hesitation (犹豫), Francis began to dig hard to save Ian from the snowy trap. In the end, he ________ it. Feeling extremely ________ , Ian hugged Francis, telling him, “I’m so glad you ________   my life today.”

5 . Jane got some terrible illness when she was four. After years of treatment (治疗), she finally became healthy.

Two years ago, while Jane was watching the Olympics, a dream came into her sweet little head — to be a swimmer.

She practiced hard and finally joined the local swimming team. The team practice, however, was a difficult start. She coughed for her first few weeks. Hearing her coughing heavily one night, I decided to pull her from it all. But Jane woke me up early the next morning, wearing her swimsuit ready to go! I told her she shouldn’t swim after a whole night’s coughing, but she just refused to rest at home.

From that day on, Jane kept swimming and didn’t miss any practice. She wanted to be the best swimmer someday.

My girl was growing and changing right before my eyes into this strong-minded person. There are moments when she felt upset of course — often she would be the last swimmer in the race. It was difficult for Jane to accept that she wasn’t a winner ever. But that didn’t stop her from trying.

Then came the final awards ceremony (颁奖仪式) at the end of the year. Jane didn’t expect any award but was still there for her friends. As the ceremony was nearing the end, I suddenly heard the head coach (教练) saying loudly, “The highest honor (荣誉) goes to Jane!”

It was the greatest moment of my daughter’s life. With all she had been through in her ten years, this was the hour of true success.

8 . The scientists who re-engineered the plastic-eating enzyme (酶) PETase have now created a new enzyme called “cocktail”, which can digest plastic up to six times faster.

PETase breaks down PET back into its building blocks, creating an opportunity to recycle plastic and reduce plastic pollution. PET is the most common thermoplastic (热塑性塑料) used to make single use drinks bottles, which takes hundreds of years to break down in the environment, but PETase can shorten this time to days. The initial discovery set up the prospect of a revolution in plastic recycling, creating a potential low-energy solution to tackle plastic waste.

Now, the same trans Atlantic team have combined PETase and its “partner”, a second enzyme called MHETase, to generate much bigger improvements: simply mixing PETase with MHETase doubled the speed of PET breakdown, and engineering a connection between the two enzymes to create a “super-enzyme” increased this activity by a further three times.

The team was co-led by the scientists who engineered PETase, Professor John McGeehan and Dr Gregg Beckham. Professor McGeehan said: “Gregg and I were chatting about how PETase attacks the surface of the plastics and MHETase chops things up further, so it seemed natural to see if we could use them together. Our first experiments showed that they did work better together, so we decided to physically link them. It took a great deal of work, but it was worth the effort—we were delighted to see that our new enzyme is up to three times faster than the separate enzymes.”

The original PETase enzyme discovery indicated the first hope that a solution to the global plastic pollution problem might be within grasp, though PETase alone is not yet fast enough to handle the tons of PET bottles. Combining it with a second enzyme and finding they work even faster together means another leap forward has been taken towards finding a solution to plastic waste. PETase and the new combined MHETase-PETase both work by digesting PET plastic. This allows for plastics to be made and reused endlessly, reducing our reliance on fossil (化石) resources.