Recently some American scientists have given a useful piece of advice to people in industrialized nations．They say people should eat more of the same kind of food eaten by humans living more than 10,000 years ago．{#blank#}1{#/blank#}

    The scientists say that the human life has changed greatly．Our bodies have not been able to deal with these changes in lifestyle and this had led to new kinds of sicknesses．{#blank#}2{#/blank#}So they are called "diseases of civilization"．Many cancers and diseases of the blood system are examples of such diseases.

    Scientists noted that people in both the Old Stone Age and the New Stone Age enjoyed very little alcohol or tobacco, probably none．{#blank#}3{#/blank#} However, a change in food is one of the main differences between life in ancient times and that of today.

 Stone Age people hunted wild animals for their meat, which had much less fat than domestic ones．They ate a lot of fresh wild vegetables and fruits．They did not have milk or any other dairy products, and they made very little use of grains．{#blank#}4{#/blank#} We eat six times more salt than our ancestors．We eat more sugar．We eat twice as much fat but only one third as much protein and much less vitamin C.

    {#blank#}5{#/blank#} But scientists say that we would be much healthier if we eat much the same way the ancient people did, cutting the amount of fatty, salty and sweet food.

 A．Modern people used to suffer from "diseases of civilization".

 B．People today probably don't want to live like our ancestors.

 C．These new sicknesses were not known in ancient times.

 D．Ancient people also got lots of physical exercise.

 E．In that case, they would live much healthier.

 F．But today, we enjoy eating a lot of these.

 G．Stone Age people lived a simple life.

    For many people, history classes are seen as no more than requirements for getting degrees in chemistry, biology, business, marketing, etc. {#blank#}1{#/blank#}． Below are a few reasons why it's vital that today's people continue to learn about the past.

    Understanding where people come from plays a key role in understanding who they are.{#blank#}2{#/blank#} For this reason, it's extremely important to learn history in order to understand why people are the way that they are.   

    Through history classes, you can experience a shift (改革) in the way you think. {#blank#}3{#/blank#}It's important to develop minds to be able to consider problems from different angles. Finally, this shift can improve your ability to analyze and understand situations, to make educated decisions and to learn how to weigh the consequences related to each choice before you.

    {#blank#}4{#/blank#}The idea that history repeats itself is rooted in truth. From wars to fashion to political trends, historians are often able to make predictions about the future based upon the past. By having a deep understanding of what happened in the past, today's people can better prepare for brighter futures by making the right decisions—instead of repeating old mistakes.

    Many people may not believe that a degree in history can lead to a well-paid job. In fact, students who graduate with degrees in history can become lawyers, business owners, think tank members, educators, leaders in historical organizations writers and so on. {#blank#}5{#/blank#}.

    A dog's mind is only equal to that of a two-year-old baby. {#blank#}1{#/blank#} So, they are probably the first to notice any change in the behavior of their masters. Let's do some deep-digging to understand the amazing ability of a dog.

    They sense your feelings. Isn't it strange? {#blank#}2{#/blank#} This is true. A study published in the Animal Cognition（认知）journal says that dogs are known to come to people who appear sad or depressed. It doesn't matter if the person is their owner or a stranger. They have an ability to sense sadness and are attracted to troubled souls.

    {#blank#}3{#/blank#} Dogs can easily tell when you're playing with favorites, and if you reward or play more with other pets, your dog might notice it and feel uncomfortable. As they can't say how they feel, they will scratch, yawn or lick their mouths.

    They smell fear. Let's say you are faced with your worst fear. Would you get scared and run away or just face it? Before choosing how to deal with it, you should remember one thing. {#blank#}4{#/blank#} Research shows that dogs often sense their master's response in dangerous situations. If you fear something and choose to back away, chances are that your pet is going to do the same thing.

    They're watching you. We are all raised as responsible individuals who are taught to respect elders, obey the law and help out people in need from time to time. {#blank#}5{#/blank#} But if you have a dog at home, it is time to be serious about them. Dogs like generous people. So just be careful around your pet; it may judge you on how you behave with others.

A. They sense health problems.

B. They understand when ignored.

C. They know when no one's looking at them.

D. You would be setting an example to your pet.

E. Every time you feel sad, your dog just knows it.

F. But dogs are able to sense everything around them.

G. However, not all of us take these three things seriously.

    After you go to college, you'll find you have to buy a lot of textbooks.{#blank#}1{#/blank#}If you want to make ends meet and successfully make it through college, you have to find ways to save on college textbooks. Here are some of the tips that would help you cut back and manage your book expense.

    {#blank#}2{#/blank#}The first thing you want to do when you need a specific book is to go to the bookstore. But the most effective way to save money on college books is to stay away from the bookstore. While it is more convenient to purchase textbooks in the bookstore, it could cost you a lot of money.

    Buy your books online. You can save a lot of money when you purchase your books online. You can buy college textbooks from Amazon, Half, CENGAGE Learning, Barnes&Noble and other websites. If you want to save money on college books，it is best to check BigWords.{#blank#}3{#/blank#}

    Rent your college textbooks. If you feel you are not going to use the book after the end of the semester, it is best to rent it instead.{#blank#}4{#/blank#}You can check campus book rentals, bookbyete, bookrenter, chegg and ecampus. This can save you a lot of money on textbooks.

    Check your university library. ff you do not need the book all the time, it is best to do your research in the university library instead.{#blank#}5{#/blank#}In this way, you can ensure the book is available when you need it. You can also use the interlibrary loan system.

A. Do not go to the bookstore.

B. You can rent books from other students.

C. College textbooks can be very expensive.

D. Buy books from second-hand bookstores.

E. Many websites and booksellers rent books.

F. You'd better order the book you need ahead of time.

G. This website will help you find promotions, discounts and other deals.

    Helen Keller once wrote, “The unselfish effort to bring cheer to others will be the beginning of a happier life for ourselves.”{#blank#}1{#/blank#}The UN has set December 5 as Internatuional Volunteers Day to give recognition to these people.

    Nineteen-year-old Andrew Makhoul was a communications major at the University of Pennsylvania. It was coming up to spring break, but unlike his classmates, Makhoul wasn't planning on spending the break relaxing.{#blank#}2{#/blank#}

    He traveled to Guatemala. He went to an orphanage（孤儿院）in one of the most violent and poor parts of Guatemala city.{#blank#}3{#/blank#} Although he didn't speak much Spanish, he found communication wasn't a problem: “You communicated with love.” And what he gave out, he got back: “You could see love when you looked in their eyes.”

    Makhoul's first time as a volunteer only lasted a week, but by the end of that week, he knew he'd be back in the future.

    {#blank#}4{#/blank#}The UN highlighted the case of Palestinian women who are survivors of breast cancer. As part of the UN's Aid and Hope Programme for Patient Care, the women have been volunteering their time to create low-cost breast prosthetics（假体）to be distributed to women for free, among whom Shahd El-Swerki is a brilliant example.{#blank#}5{#/blank#} By the end of her time there, she admired these women who are “not only survivors but also volunteers”.

    About 2,400 years ago, Greek philosopher Aristotle said, “The essence（本质）of life is to serve others and do good.” Volunteers all around the world are making these words come true, each and every day.

A. It depends upon volunteers to stay open.

B. She worked with the women as part of the programme.

C. Here, we tell two volunteering stories from around the globe.

D. Sometimes, volunteers themselves live with huge challengers.

E. He decided to spend his time doing something useful for people.

F. Volunteers want to do their best to make the world warmer and more beautiful.

G. These words certainly prove true for the millions of volunteers all over the world.

Learning, Fast and Deep

    Over the past five years researchers in artificial intelligence have become the rock stars of the technology world. A branch of AI known as deep learning, which uses neural(神经的) networks to scan through large volumes of data looking for patterns, has proven so useful that skilled practitioners can command high six-figure salaries to build software for Amazon, Apple, Facebook and Google.

    The standard route into these jobs has been a PhD in computer science from one of America's top universities. Earning one takes years and requires a personality suited to academia, which is rare among more normal folk.

    That is changing.

    Last month fast.ai, a non-profit education organization based in San Francisco, kicked off the third year of its course in deep learning. Since its foundation it has attracted more than 100, 000 students around the globe from India to Nigeria. The course and others like it, come with a simple idea: there is no need to spend years obtaining a PhD in order to practise deep learning. Creating software that learns can be taught as a craft, not as a high intellectual pursuit to be undertaken only in an ivory tower. Fast. ai's course can be completed in just seven weeks.

    To make it accessible to anyone who wants to learn how to build AI software is the aim of Jeremy Howard, who founded fast.ai with Rachel Thomas, a mathematician. He says school mathematics is sufficient. "No. Greek. Letters," Mr. Howard intones, pounding the table with his fist for punctuation.

    Some experts worry that this will serve only to create a flood of unreliable AI systems which will be useless at best and dangerous at worst. In the earliest days of the Internet, only a select few nerds, namely computer holies with specific skills, could build applications. Not many people used them. Then the invention of the World Wide Web led to an explosion of web pages, both good and bad. But it was only by opening up to all that the Internet gave birth to online shopping, instant global communications and search. If Mr. Howard and others have their way, making the development of AI software easier will bring forth a new crop of fruit of a different kind.