Tang Dynasty poets sang for about three centuries in different tones. There were many famous poets living in the Tang period such as Li Bai, Du Fu, Bai Juyi and Li Shangyin. Poems of the Tang Dynasty edited in the Qing Dynasty is a collection of about 48,900 poems that were written by over 2,200 poets. But it didn't cover all the poems of the Tang Dynasty.

    During the Tang Dynasty, poems were recited when lovers walked under the moonlight. Poems were also recited when soldiers fought on the battlefield. People recited them in the open air or at temple fairs.

    In the Tang Dynasty scholars had to be poets. Their readers were not only people of high social position but also common people. Poets recited poems; women singers sang poems and other ranks of people, including old women and children, read Tang poems. This atmosphere affected foreigners who visited the country at that time. As a result, Tang poetry was introduced to some adjacent countries, like Japan and Vietnam.

    Tang poetry is a most brilliant page in the history of ancient Chinese literature. It's a miracle in the cultural history of mankind. The Tang Dynasty was a powerful empire with a vast territory. It inherited Chinese civilization that went back to ancient times, and was combined with the best of other cultures and adopted the benefits of other nations in the world. Tang poetry wasn't the only spiritual wealth created by the Tang Dynasty people. Philosophy and religion, handwriting and painting and music and dance all gained new peaks of development. Tang poetry, however, was the jewel in the crown and its greatest achievement.

    Since English biologist Charles Darwin published On the Origin of Species in 1859, scientists have vastly improved their knowledge of natural history. However, a lot of information is still of the speculation, and scientists can still only make educated guesses at certain things.

    One subject that they guess about is why some 400 million years ago, animals in the sea developed limbs (肢) that allowed them to move onto and live on land.

    Recently, an idea that occurred to the US paleontologist (古生物学家) Alfred Romer a century ago became a hot topic once again.

    Homer thought that tidal (潮汐的) pools might have led to fish gaining limbs. Sea animals would have been forced into these pools by strong tides. Then, they would have been made either to adapt to their new environment close to land or die. The fittest among them grew to accomplish the transition (过渡) from sea to land.

    Romer called these earliest four-footed animals “tetrapods”. Science has always thought that this was a credible theory, but only recently has there been strong enough evidence to support it.

    Hannah Byrne is an oceanographer (海洋学家) at Uppsala University in Sweden. She announced at the 2018 Ocean Sciences Meeting in Oregon, US, that by using computer software, her team had managed to link Homer's theory to places where fossil deposits (沉积物) of the earliest tetrapods were found.

    According to the magazine Science, in 2014, Steven Balbus, a scientist at the University of Oxford in the UK, calculated that 400 million years ago, when the move from land to sea was achieved, tides were stronger than they are today. This is because the planet was 10 percent closer to the moon than it is now.

    The creatures stranded in the pools would have been under the pressure of “survival of the fittest”, explained Mattias Green, an ocean scientist at the UK's University of Bangor. As he told Science, “After a few days in these pools, you become food or you run out of food... the fish that had large limbs had an advantage because they could flip (翻转) themselves back in the water.”

    As is often the case, however, there are others who find the theory less convincing. Cambridge University's paleontologist Jennifer Clark, speaking to Nature magazine, seemed unconvinced. “It's only one of many ideas for the origin of land-based tetrapods, any or all of which may have been a part of the answer,” she said.

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    A spaceship is flying to the sun in summer 2018! It will be the first-ever to a star and will be one of the biggest achievements space exploration (探险) in human history. The purpose is to study the sun's outer atmosphere and better understand how stars work.

The spaceship, with no man inside, will fly within 4 million miles of the sun's surface - right into the solar atmosphere, where the temperature is over 4,500℃. To protect the spaceship, it is covered with a 12cm-thick coating.

    The spaceship is called Parker Solar Probe and it is named after Eugene Parker, a professor from the University of Chicago. It's the first NASA spaceship to be named after a researcher who is still alive. In 1958, Eugene Parker first created the term “solar wind”-the sun sending out a flow of particles (颗粒) and energy.

    “The spaceship is going where it has never been before. It's very exciting that we'll finally get to know more about the solar wind. I'm sure there will be some surprises. There always are,” said Professor Parker.

    Parker calls it a heroic scientific space adventure, and he means that the spaceship will have to experience high temperatures and sun radiation (辐射). “The spaceship is going to do the hottest and fastest work. I love to call it the coolest hottest work under the sun,” said Scientist Fox Nasa.

    Many people tend to complain about not having good friends in their lives. Sadly, they seem to think that their own company is not enough to make them happy. Nothing could be further from the truth though. In order to get along with others, the first thing you need to do is learn to get along with yourself. Only in this way will you succeed in developing healthy, solid relationships with others.

    Listen to your inner voice. Remember that inner voice that keeps whispering to you what you really want and need as well as what you do not really want and need. It is about time you started listening to it. In order to get to know yourself in depth, it is important to learn and accept what you want and what you do not want.

    Learn to enjoy your own company. You will be surprised to find out how many things you can do by yourself and actually have fun in the process. Reading romantic novels, poetry or science fiction is only a few of the things that you can do by yourself, which not only can offer you hours of enjoyment, but also the chance to get to know yourself better.

    Satisfy yourself. Pay special attention to your personal hygiene(卫生). Do your hair and nails often and experiment with new styles. Follow a healthy diet and exercise regularly to stay in good shape. No matter how busy your daily schedule is, always find at least an hour per day for yourself, when you can either relax doing absolutely nothing, or doing something that you enjoy most.

    Learn to respect your own boundaries. Find out what your boundaries are and learn to respect them. You are the only one who knows what you can accept and what you cannot.

    Susan couldn't help it. She and her friends began lunch with cheese. Then they ate cheeseburgers and drank milk. Things seemed fine, but then suddenly Susan's stomach started making noise. Her stomach hurt, and, racing to the restroom, she had terrible gas! She was so ashamed. She had been so excited to go to lunch with her friends that she totally forgot to watch how many dairy products (奶制品) she ate! Susan is lactose intolerant (乳糖不耐受的), and eating too many dairy foods can make her feel really sick.

    Lactose intolerance means that the body can't easily digest (消化) a special sugar called lactose. Unfortunately for Susan and millions of other people with this problem, lactose is found in almost all dairy products — cheese, milk and ice cream.

    Our body uses lactase (乳糖酵素) to break lactose into a simpler form of sugar. Once lactose is broken down, it's easy to digest and it provides great energy for the body. But people like Susan don't have enough lactase to break down all the lactose they take in. So, about half an hour to two hours after eating dairy­rich foods, their stomachs begin to hurt and they have gas, making their stomachs get bigger. Sometimes they even get diarrhea (腹泻) when they eat too many dairy foods.

    So how can someone living with this problem still eat out with his or her friends? Here are some tips. If you're going to eat a dairy­rich food like ice cream, eat something that doesn't have any dairy with it, like a salad or a sandwich without cheese. This will help slow digestion, and your body will have time to create more lactase.