Americans spend their free time in various ways.

    America is a country of sports — of hunting, fishing and swimming, and of team sports like baseball and football. Millions of Americans watch their favorite sports on television. They also like to play in community orchestras (管弦乐队), make their own films or recordings, go camping, visit museums，attend lectures, travel, garden, read, and join in hundreds of other activities. The people also enjoy building things for their homes, sewing their own clothes, even making their own photographs. They do these things for fun as well as for economy.

    But as much as Americans enjoy their free time, the country is at the same time a "self-improvement" country. More than 25 million adults continue their education, chiefly by going to school in the evening, during their own free time, at their own expense. Added to the time spent on personal activities, Americans a1so devote a great amount of their time to the varied needs of their communities. Many hospitals, schools, libraries, museums, parks, community centers, and organizations that assist the poor depend on the many hours citizens devote to these activities, often without any pay. Why do they do it?

    There are several answers. The idea of cooperating and sharing responsibility with one another for the benefit of all is as old as the country itself.

    When the country was first founded in 1776, it was necessary for the settlers to work together to live. They had crossed dangerous seas and risked all they had in their struggle for political and religious freedom. There remains among many Americans a distrust of central government. People still prefer to do things themselves within their communities, rather than give the government more control.

    Sometimes people offer their time because they wish to accomplish something for which no money is paid, to do something that will be of benefit to the entire community. It is true that some people use their leisure because they are truly interested in the work; or they are learning from the experience.

    No matter what the reason is, hundreds of thousands of so-called leisure hours are put into hard, unpaid work on one or another community need.

Whenever Michael Carl, the fashion market director at Vanity Fair, goes out to dinner with friends, he plays something called the "phone stack" game: Everyone 1 their phones in the middle of the table; whoever looks at their device before the check arrives 2 the tab (账单).

Brandon Holley, the former editor of Lucky magazine, had trouble 3 her mobile phone when she got home from work. So about six months ago, she 4 putting her phone into a milk tin the moment she walked in. It remains there until after dinner. And Mare Jacobs, the fashion designer, didn't 5 to sleep close to a buzzing gadget (小装置). So he 6 digital devices from his bedroom — a house rule he 7 with audiences during a recent screening of Disconnect, a film that shows how technology has alienated (使疏远) people from one another.

As smart phones 8 to make their way into our lives, and wearable devices like Google Glass 9 to destroy our personal space even further. Whether it's a physical 10 (no iPads at the dinner table) or a conceptual (精神上的) one (turn off devices by 11 p.m.), users say these disconnecting 11 are improving their relationships.

"Disconnecting is a luxury that we all 12," said Lesley M. M. Blume, a New York writer who keeps her phone away from the dinner table at home. "The expectation that we must always be 13 to employers, colleagues and family creates a real problem in trying to 14 private time. But that private time is more important than ever."

A popular method for disconnecting is to choose a box for your cellphone, like the milk tin that Ms. Holley uses. "15 my phone is buzzing or lighting up, it's still a distraction (分散注意力的事), so it 16 in the box." said Ms. Holley. Others choose new 17. "No screens after 11 p.m." said Ari. Melber, a TV host. "Now evenings are more 18 and I am sleeping better." he added.

Sleep is a big factor, which is why some 19 to leave their phones out of their bedrooms. "I don't want to sleep next to something full of photos and emails." said Peter Som, a fashion designer, who keeps his phone plugged in in the living room overnight. "It 20 is a head­clearer and distinguishes daytime and sleep time."

    It was a terrible day. Snow had been falling all day long making the trip 1. I would rather have been in my warm home than drive along on such a cold day, but I didn't have a 2. I had to have my paper work handed in and then 3 my son.

    The snow continued to fall as we drove along for the 15-mile trip back home. I slowed the car and 4 at my son in his heavy coat as he looked 5 out of the window with a blank expression. In the 6 of the world he was looked upon as a mentally disabled child. 7, over the years what I saw was a beautiful, kind and 8 soul. He had shown me more about love than I could have ever 9 on my own.

    I slowed the car even more as we 10 a sharp curve (弯). As we rounded it I saw a shivering (颤抖的), young woman in a 11 jacket walking in the snow storm . I pulled over and let her in. She was heading for her Mom's house to visit her 12 whom she hadn't seen for months. She had experienced a lot of disappointments and 13. Yet, she still held out hope for a new job and tried to 14 a new life for her son and herself.

    I took her as 15 as I was able to and dropped her off. She thanked me for the 16 and I told her I wished I could have done more to help. Then as we were about to leave, my sweet son took off his coat, 17 down the window and gave it to her. She put it on, smiled and 18 to us as we pulled out on the road.

    In this world we will 19 many problems and challenges. Sometimes it seems that our entire lives are a trip down a curvy and dangerous road. Yet the power of 20 takes us straight back to a broad smooth highway.

He be an instructor in the Taijiquan Community.

1）发出邀请；

2）时间和地点；

3）活动安排。

注意：1）词数100左右，开头和结尾已经出,不计入总词数；

2）可适当增加细节,以使行文连贯。

Dear Frank,

    Having heard that you won't return to your country this summer vacation,

    I look forward to receiving your earliest reply!

Yours,

Li Hua

—I study English               talking with foreign students.

Imagine you're standing in line to buy an after-school snack at a store. You step up to the counter and the cashier scans your food. Next, you have to pay. But instead of scanning a QR code (二维码) with your smartphone, you just hold out your hand so the cashier can scan your fingerprint. Or a camera scans your face, your eyes or even your ears.

Now, this type of technology might not be far away. As technology companies move away from the traditional password biometric (生物特征识别的) security, which includes fingerprint, face and voice ID, is becoming increasingly popular.

In 2013, Apple introduced the iPhone 5s, one of the first smartphones with a fingerprint scanner. Since then, using one's fingerprint to unlock a phone and make mobile payments has become commonplace, bringing convenience to our lives. And since last year, Samsung has featured eye scanning technology in its top smartphones, while Apple's new iPhone X can even scan a user's face. But despite its popularity, experts warn that biometrics might not be as secure as we'd imagined. "Biometrics are ideally good, but in practice, not so much", said John Michener, a biometrics expert.

When introducing the new iPhone's Face ID feature, Phil Schiller, Apple's senior vice president, said, "The chance that a random person in the population could look at your iPhone X and unlock it with their face is about one in a million." But it's already been done. In a video posted on community website Reddi, two brothers showed how they were each able to unlock the same iPhone X using their own face. And they aren't even twins.

"We may expect too much from biometrics," Anil K. Jain, a computer science professor at Michigan State University, told CBS News. "No security systems are perfect. "

Earlier this year, Jain found a way to trick biometric security. Using a printed copy of a thumbprint, he was able to unlock a dead person's smartphone for the police, "It's good to see biometrics being used more," Jain told CBS News, "because it adds another factor for security. But using multiple security measures is the best defense."

Most of the wind available on land is too gentle to push commercial wind turbine(涡轮机), but now researchers in China have designed a kind of "tiny wind turbine^,, that can use wind energy from breezes as little as those created by a quick walk. The new device is not technically a turbine. It is a nanogenerator made of two plastic strips in a tube that clap together when there is airflow. Like rubbing a balloon to your hair, the two plastics become electrically charged after being separated from contact, a phenomenon called the triboelectric effect. But instead of making your hair stand up like Einstein's, the electricity generated by the two plastic strips is captured and stored.

"Our intention isn't to replace existing wind power generation technology. "Our goal is to solve the issues that the traditional wind turbines can't solve?" says Ya Yang, a researcher from Beijing Institute of Nanoenergy and Nanosystems. "Unlike wind turbines that use coils and magnets (磁石) where the costs are fixed, we can pick and choose low-cost materials for our device. Our device can also be safely applied to nature reserves or cities because it doesn't have the rotating (旋转) structures.

Yang says he has a small vision and a big vision for the project's next steps. In the past, Yang and his colleagues have designed a nanogenerator as small as a coin, but he wants to make it even tinier and more compact with higher efficiency. Yang is also looking to make the device bigger and more powerful. "I'm hoping to scale up the device to produce 1,000 watts. We can place these devices where traditional wind turbines can't reach. We can put it in the mountains or on the top of buildings for sustainable energy.

Two British teachers have broken the world record for the longest journey in a tuk-tuk after pulling their failing vehicle for 43 miles. Richard Sears and Nick Gough traveled 37,500 kilometers around the world and passed through 37 countries. They did this to support grassroots education project in Africa, Asia and South America.

The pair, who set off from London, thought their expedition was over when the vehicle started to fail. When the tuk-tuk broke, they were only 70 kilometers from their destination. They decided to pull it the rest of the way. The tuk-tuk, which weighs 800 kilograms, was pulled in turns by Rich and Nick over three days. On arrival in Chepen, Peru, they discovered a mechanic who specialized in tuk-tuks and managed to fix it.

The pair were back on the road and aiming for their next goal. Along their journey they had to tackle deserts and jungles. They also survived close encounters with elephants in Uganda and Botswana and an accident in Malaysia. The greatest hardship on the tuk-tuk was the mountain ranges lying in their path, including the Alps, the Himalayas and the Andes.

Nick and Richard uncovered some inspirational projects across Africa, Asia and South America. They witnessed firsthand the educational challenges facing these areas today. They joined street children in the slums of Cairo, Khartoum, Kampala, Mumbai and Phnom Penh. They visited Congolese refugees (难民) in camps in Eastern Burundi. They witnessed how education could free sex-workers in Delhi and victims of human trafficking in Nepal.

The pair established The Tuk Tuk Educational Trust, a U. K. registered charity.

Talking about their motivation, Richard said: "The world's leaders have made a commitment to achieving universal primary education but, in spite of this pledge (誓言,承诺), over 57 million primary-aged children worldwide are still out of school; many more are in school, though still cannot access quality learning opportunities. "