Since 1964，colleges and universities in the U. S. have used Test of English as a Foreign Language，or TOEFL，to measure an international applicant's（申请人的）level of English. Universities in English-speaking European countries began using the International English Language Testing System，or IELTS，in 1989. These two tests have been the main choices for English ability testing in higher education admissions for international students until now.

In recent years，several companies have developed new English language tests that are low-cost and easy to use. And they aim to do more than just offer greater choices in the admissions process.

Founded in 2012, Duolingo creates software that teaches users many different languages, including English. In 2014, the company launched its own test of English language ability.

Jennifer Dewar works with Duolingo, helping to develop the test. She formerly worked as an admissions official at Washington University in St. Louis, Misouri. The school is one of hundreds of colleges, universities and other organizations in and outside the U. S. that now accept the test results for international admissions into their study programs.

Dewar says Duolingo created the test to lower the barriers to higher education for people worldwide, especially those in developing countries.

TOEFL and the IELTS cost about $ 300. They are given in a limited number of centers around the world. Some test-takers have to travel to take the tests, adding to the costs. Duolingo offers its test entirely over the Internet for $ 49. All test-takers need is access to a computer with a microphone，listening device and self-facing camera.

TOEFL，the IELTS and Duolingo measure a person's English reading，listening，speaking and writing abilities. But it takes about 45 minutes to complete a Duolingo test，compared to three or four hours for TOEFL or the IELTS. It is possible because Duolingo uses artificial intelligence（人工智能）to adapt to test-takers' abilities，using fewer questions to measure their skills.

   Chester Greenwood was freezing. It was in 1873 and Chester was _________ a new pair of ice skates. The 15-year-old was getting _________because he couldn't keep his ears _________ or protect them from the bitter cold. He tried wrapping a _________around his head but it was too _________and itchy. Besides，who can _________ with a scarf tied around their heads？

To _________his problem，Chester made two ear-shaped rings from wire and asked his grandmother to sew beaver fur and cloth _________them. Over the years his new invention，the earmuff，improved-a steel band was added，so it became _________and tiny chains were added so it would ____________in pockets. Finally Chester had his own ____________，Greenwood's Ear Protector Factory. He made a ____________providing ear protectors for the US soldiers during World War I.

Chester ____________over 100 products during his lifetime. Some of them are the wide bottom kettle，the spring steel rack，the folding bed，the shock absorber（减震器）that ____________today's airplane landing gear（起落架）and bearings to keep ____________from being pulled off，ensuring that they touch the ground safely. The Smithsonian Institution named Chester one of America's 15 ____________ inventors.

The town of Farmington, Maine, where Chester was born, has an annual holiday to ____________the inventor. December 21st is Chester Greenwood Day and people all over the state of Maine ____________in the celebration. Farmington has a parade on the first Saturday in December and everyone from kids to old people shows up ____________earmuffs. He invented over 100 products ____________Chester will always be remembered for inventing the earmuffs when he was 15.

   Trying to fight against the nation's food waste problem，Denmark opened the world's first supermarket that sells expired（到期的）or damaged products.

Ever since it was opened in Copenhagen，people have been standing in line outside WeFood for a chance to buy discounted items that would otherwise have ended up being rubbish because of damaged packing or very short use-by dates. Food，cosmetics，and other household items at WeFood are priced at least 30% to 50% lower than those at regular stores.

It's foolish to throw away or let food go to waste," said Hansen, former Minister for Food and Environment." It's bad for the environment and obviously it is money spent on nothing. A supermarket like WeFood makes so much sense and is an important step in the battle to fight against food waste."

While Denmark alone is said to waste about 700,000 tons of food this year, the United Nations has stated that globally, food waste adds up to 1.3 billion tons. It is really shocking, considering that about795million people in the world are still short of food. Denmark, however, has taken measures. As a result, it wastes 25% less food than it did five years ago.

The We Food project is cooperation between the Food Bank and Dan Church Aid. Together they have collected over s 150，000 over the past years. They faced many problems while convincing the government to permit the sale of expired or damaged products. They were finally allowed to carry out the project，and the store is now specially run by volunteers. The money it earns is used to provide funds（基金）for Dan Church Aid's other projects in developing nations.

If We Food can successfully maintain its goods deliveries and remain popular in the long term，Dan Church Aid plans to open many other branches across Denmark.

   A new keyboard can tell whether you are its owner. The keyboard records information about the typing pattern（模式）and sends it to a computer program. The program then checks to see if the pattern matches the right user. If not, an alarm sounds, and the computer locks the typist out. It locks out everyone else, even if the person knows the password. What's more, this equipment needs no batteries. It collects all the energy it needs from your actions of typing. Besides, the keyboard is also self-cleaning and the keys are free of damage from water, oil and dirt.

The keys of the new keyboard are made of the same inexpensive plastic that might be found on any other standard keyboard. But instead of being smooth, the keys have millions of tiny plastic nanowires（纳米线）on their surface area, increasing the effective contact areas between the plastics and fingers. This guarantees that there's enough power to run the keyboard as someone types.

Liming Dai, a scientist, did not work on the new keyboard, but he thinks the design could be important in getting better performance from a variety of equipment. "It could also be applied to a touch screen, for example, "Dai says. " Then smart phones and notepads could collect energy from someone's actions of typing or drawing. "

"Future work might make the keyboard even more useful, "Dai adds. " A later design might build tiny capacitors onto the nanowires, "he suggests. Capacitors are little devices that temporarily store electric charge. Those might then be LEDs to light a keyboard in the dark.

Zhonglin Wang is a co-designer of the new keyboard. His team has built a working model of the keyboard. "If a company decides to fund（资助）its production, this keyboard could be in stores in as few as two years, "says Wang.