While dog keepers realize their dogs can read their moods accurately,scientists have always been a little doubtful.Now thanks to some researchers at the University of Veterinary Medicine in Vienna,Austria,we finally have some convincing evidence.

    For their study,biologist Corson Miller and his team exposed eleven selected dogs to digital images of women that were either angry or happy.Half the dogs were rewarded for touching the screen when shown a happy face,while the other half got their treat for selecting those that appeared angry.

    Interestingly,the dogs were not provided with the entire face.Some dogs were shown only upper halves while the others observed lower halves.That's because the scientists believe humans show their emotions on their entire face.

    After some training like how to recognize small differences like the wrinkles between the eyes or the changes in their shape that accompany the happy or angry expressions,the dogs were mostly able to identify the correct expression not only on a familiar face but on a strange face.The researchers concluded the dogs were smart enough to read human emotions.

    They also found those being trained to read angry expressions took a longer time to learn.They guess it may be because dogs find angry faces disgusting,causing them to withdraw quickly.However,once the smart dogs realized they were getting rewarded,the trepidation seemed to disappear.In fact,the dogs had such a good time playing the computer "game" that scientists had a hard time keeping them away from the touch screens after the study was completed.

    The researchers also noticed only dogs with a male owner had a harder time understanding the expressions correctl. Since the touchscreen models were all females, this confirmed what has been observed in previous studies-dogs are more efficient at reading facial expressions of people that are the same gender as their owner.

    Alaska's state fair, which runs until September 5^th, began as a celebration among residents of the Mantanuska Colony, a project under which 200 farm families were moved to Alaska to see whether agriculture could be possible in the coldest state. The state fair lives on, but little more than a decade after the start of the project most of the participants had abandoned their farms. The project was widely seen as a flop.

    In this state, glaciers cover 300 times more acres than farms. Only 5% of the food consumed is grown locally, compared with 81% nationwide. The growing season is short and summer temperatures chilly. Tomato plants wither(凋谢). Fruit trees, in most parts of the state, are just a dream.

    Enter the high tunnel: a greenhouse consisting of a metal frame with plastic stretched across it. Its few millimeters of plastic separate crops inside from the great outdoors. But this is enough for Alaskan growers to produce tomatoes as well as sweetcorn, peaches and kiwi fruit, and to boost production of crops by a quarter or more.

    In a place where no one blinks(眨眼) if you call yourself a fisherman, boat captain or gold miner, an increasing number of Alaskans are thinking of themselves as people who grow food. Since the start of the programme, the number of farms registered(登记)with the state has nearly doubled. Local restaurants have begun shaping their menus around what neighboring farms can grow.

    Eight decades ago, the Mantanuska Colony tried to turn farmers into Alaskans. Today, the high tunnels are turning Alaskans into farmers.

    It seems that technology could be changing the places where we live. A project conducted by Johann Siau, a senior lecturer at the University of Hertfordshire's School of Engineering and Technology, has built on the university's InterHome project aimed to create a home that supervises people living at home who are weak or elderly.

    “We've developed a wristband type of device（装罝）,” said Johann Siau, “which allows us to monitor the condition of an elderly person, or whoever is wearing the device. It allows us to collect data of a person to see if the person has fallen or is away from where they are supposed to be. It connects an elderly person with an assisted living type of device with the InterHome.” The assisted living project is part of the university's wider InterHome project, which is the development of a smart house. The house stores the usage patterns of the person living there and can adapt to make it use as little energy as possible. Connecting the two together and building the service element（元素）allow us to introduce the assisted living idea to care for the elderly. It's very important that these technologies are there to help and support rather than to replace any of the existing services.

    The InterHome is not just a prototype（样品）or a vehicle for research. It's a study tool to help students from different scientific backgrounds learn about and develop technology. The InterHome combines the latest broadband technology, mobile data and communication. Researchers and students make sure that all the technology works together. Students get experience by developing new hardware and software themselves. It requires a variety of skills from students—electronic engineers, computer students, design students and so on. “The present plan we are working on is a smart home project in Watford with some commercial companies, ” said Johann Siau. “We are looking at how a smarter home can provide extra value services.”

    I was born on the 17th of November 1828, in the village of Nam Ping, which is about four miles southwest of the Portuguese Colony (殖民地) of Macao, and is located on Pedro Island lying west of Macao, from which it is separated by a channel of half a mile wide.

    As early as 1834, an English lady, Mrs. Gutzlaff, wife of a missionary to China, came to Macao. Supported by the Ladies' Association in London for the promotion of female education in India and the East, she immediately took up the work of starting a girls' school for Chinese girls, which was soon followed by the opening of a boys' school.

    Mrs. Gutzlaff's comprador(买办) happened to come from my village and was actually my father's friend and neighbor. It was through him that my parents heard about Mrs. Gutzlaff's school and it was doubtlessly through his influence and means that my father got me admitted into the school. It has always been a mystery to me why my parents should put me into a foreign school, instead of a traditional Confucian school, where my big brother was placed. Most certainly such a step would have been more suitable for Chinese public opinion, taste, and the wants of the country, than to allow me to attend an English school. Moreover, a Chinese belief is the only avenue in China that leads to political promotion, influence, power and wealth. I can only guess that as foreign communication with China was just beginning to grow, my parents hoped that it might be worthwhile to put one of their sons to learning English. In this way he might become an interpreter and have a more advantageous position to enter the business and diplomatic world. I am wondering if that influenced my parents to put me into Mrs. Gutzlaff's School. As to what other sequences it has eventually brought about in my later life, they were entirely left in the hands of God.

    On April 2, we said goodbye to Tiangong I, China's first space lab. According to the China Manned Space Agency（中国载人航天）, Tiangong I re-entered the Earth's atmosphere （大气层）and fell into the South Pacific Ocean.

    There are many spacecraft that are still in orbit above the Earth. They are flying at heights ranging from 300 to 1,000 kilometers. After finishing their trips, they will all re-enter the Earth's atmosphere like Tiangong I.

    There are two types of re-entries：controlled（受控的）re-entry and uncontrolled re-entry.

    Some satellites（卫星）and manned spacecraft come back to the Earth in a controlled re-entry. Scientists calculate（计算）the path of the falling spacecraft and its speed. They can guide the spacecraft to fall in a chosen area. In 2017,Tianzhou I, China's first cargo（货运）spacecraft, was directed to fall in the South Pacific Ocean.

    Some spacecraft may have problems while in space, or are simply no longer usable after a certain amount of time.  These craft come back in an uncontrolled re-entry.  It is hard to tell when and where these spacecraft will fall until the last few hours. The US space station Skylab came back partially uncontrolled in 1979. Parts of the station fell in western Australia, but no one was injured.

    During re-entry, most of the spacecraft will burn up while passing through the Earth's atmosphere. Only a small amount of the debris（碎片）will reach the ground.

    The debris typically ends up falling into the ocean, China Daily reported. Tiangong I weighs about 8.5tons. The amount of debris that falls to the Earth might be about 1 to 1.5 tons, the Beijing News reported.  That is about the same weight as a car.

    A new study suggests climate conditions in the Sahara Desert, one of hottest, driest and most deserted areas in the world, have changed from wet to dry a about every 20,000 years.

    But previous evidence has suggested the Sahara did not always experience such extreme heat and dry conditions. At times, the Sahara Ranged to a very wet climate. This permitted plants and animals to develop and grow and led to the creation of human settlements. Now, they have discovered more evidence, which, the lead researcher David Mc Gee says, supports the idea that the Sahara's climate kept changing between wet and dry about every 20,000, years.

    McGee reported these climate changes were mainly driven by changes in the Earth's(地轴)as the planet travels round the sun .This process affects the amount of sunlight between seasons. Every 20,000 years the Earth receives more strong summer sunlight. When the Earth's axis changes again, the amount of sunlight is reduced. This season change happened continuously every 20,000 years. The other part of the season produced rainy conditions, resulting in a wetter, greener, plant-rich environment. When the rainy activity weakens, the climate becomes hot and dry, like the Sahara remains today.

    The scientists based their research on dust collected from ocean sediment(沉积物)in the Atlantic Ocean bottom off the coast of West Africa. The dust contained layers (层)of ancient sediment built up over millions of years. Each layer could contain traces of Saharan dust as well as the remains of life forms. This information was used to assess over what time period the dust had built up. This led to the overall finding that the Saharan changes from wet to dry climates happened every 20,000 years.

David McGee said that today we only see the Sahara Desert as an extremely deserted and "inhospitable" place. The new study suggests that the area's climate has changes between grasslands and a much wetter environment, and back to dry climates, even over the last quarter million years. McGee says he thinks the latest research can be valuable in studying the Sahara's history as it relates to human settlement.