Life may have evolved on at least three planets within a newly discovered solar system 39 light years from Earth. Astronomers at the NASA have discovered no less than seven roughly Earth-sized worlds orbiting a dwarf star in the system. Scientists had previously identified a tiny number of "exoplanets", which are believed to have the qualities needed to support life. However, the new system contains an unprecedented(前所未有) number of Earth-sized, probably rocky planets, and is being acknowledged as an "accelerated leap forward" in the search for extraterrestrial (外星球的)life.

    Three of the new planets are said to be particularly promising because there might exist oceans. Thomas Zurbuchen, associate administrator of NASA, told a press conference in Washington: "This gives us a hint that finding a second Earth is not a matter of 'if', but 'when'."

    The planets were discovered using NASA's Spitzer Space Telescope, which was able to track how fast each of the planets crossed the star Trappist-l and completed an orbit. From this the research team calculated how far the planets were from their star, and therefore how likely they are to be habitable.

    NASA's Hubble Space Telescope is already being used to search for atmospheres around the planets. Future telescopes, including the proposed European Extremely Large Telescope and the James Webb Space Telescope, may be powerful enough to discover markers of life, such as oxygen in the atmospheres of exoplanets.

    Astronomers believe there could be as many as 40 billion potentially habitable worlds in our galaxy, the Milky Way. Prof Zurbuchen said that now was a "gold-rush phase" in the search for these exoplanets.

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    Tu Youyou, an 84-year-old female（女性）scientist, became the first Chinese to win a Nobel Prize in science on Oct 5. Before that, she ever won the 2011 Lasker Award for finding out artemisinin (Qinghaosu), which saved millions of lives. She was grateful（感激的）for the Lasker prize, but said, “It is just a scientist' duty. I will go on fighting for the health of all humans.”

    Tu kept her work in the 1960s and 1970s. In that age, Malaria (疟疾) could took away people's health. Scientists all over the world had already tried over 240, 000 times but failed. Tu Youyou, a member of the Academy of Traditional Chinese Medicine, Beijing, began to study Chinese herbs.

    Before 2011, people didn't know Tu very much. Many friends played jokes with her “the Professor of Three None's” : no degree（学位）, no study experience abroad, not a member of any Chinese national colleges. But she is hard-working. She read a lot of traditional Chinese medicine books and did a lot of researches on the disease.

    In February, 2012, Tu was named National Outstanding Females (One of the Ten) Tu is now a model of Chinese medical workers.

    On Sunday 23 April, more than 30, 000 people participated in the 2017 London Marathon, running 26.2 miles (42.2 kilometers) around the city centre.

    The London Marathon has taken place every year since 1981. At the first one just6,225 people completed the course, and since then it has grown into one of the biggest sporting events in the world. It is one of the “World Marathon Majors”, which is a competition made up of six global marathon events. The overall male and female winners receive $ 1 million in prize money between them. There are eleven people who have run every London Marathon since it began—they call themselves the “Ever Presents”.

    This year, the winners of the London Marathon were surprisingly both from Kenya— Daniel Wanjiru, who finished in 2 hours and 5 minutes, and Mary Keitany, whose time was 2 hours and 17 minutes.

    However, most marathon runners are not professional athletes. They are amateurs who have trained for months to raise money for charity or just as a personal challenge. For example, Tom Harrison took three days just to reach the run's halfway point, as he is crawling the course on his hands and knees dressed as a gorilla(大猩猩), trying to raise money and attention for the charity “The Gorilla Organization”.

    Matthew Rees was another runner to encourage people, as he stopped just before the finish line to help David Wyeth run the last 200m. They did not know each other before, but Matthew saw that David was exhausted and possibly close to collapsing, and wanted to help him finish.

    Every year there are lots of touching stories like this from the London Marathon, and it is a huge achievement even to run the 26.2 miles!

Dogs are man's best friends—they are very good for children's health. Researchers found that family pets helped to protect babies against breathing problems and infections (感染).

    A team from Kuopio University Hospital in Finland studied 397 babies born at their hospital between September 2012 and May 2015 for their first year. They found that babies who lived with a dog or a cat spent fewer weeks with ear infections, coughs or runny noses. They were also less likely to need antibiotics (抗生素) than babies in homes without a pet.

    Study author, Dr. Eija Bergroth, said dogs brought dirt and bacteria (细菌) into the home, which helped children's immune system (免疫系统) to be strong. This improved their defenses against bacteria.

    As part of the study, parents filled out weekly diaries starting when the children were nine weeks old, recording information on babies' health as well as their contact with cats and dogs. They recorded if they had fever, ear infections, coughs or running noses. They also put down whether they needed antibiotics.

    Based on those diaries, the researchers found that about a third of the children spent most of their first year with a pet dog and 24 percent in a home with a cat. And children with no dog contact at home were healthy for 65 percent of the time, compared to between 72 and 76 percent for those who did have a pet.

    The researchers also found that contact with dogs, more than cats, was tied to fewer weeks of sickness for babies.

    However, the researchers said they couldn't rule out the possibility that people who own dogs are less likely to get sick for another reason, not due to any protection offered by pets.

The hottest cities in the world

    The locations below are the hottest and also travel destinations on the planet.

    Bangkok

    According to the data, Bangkok is the hottest city on the planet﹣not because of any particularly impressive high temperatures, but because it is consistently hot all the year round. The city has an average annual temperature of 29℃, coupled with high dampness and an average of 128rainy days per year; while the highest temperature on record is 40℃.

    Timbuktu, Mali

    Located on the southern edge of the Sahara Desert, the African city of Timbuktu is similar to everything remote. It's also one of the hottest cities in the world, with a hot, dry climate offering record highs of 49℃. Throughout April, May and June, average maximum temperatures are beyond 40℃. Modern﹣day Timbuktu is slowly being swallowed by the desert and is certainly a shadow of the trade center that it once was.

    Ahvaz, Iran

    Built on the bank of the Karun River, Ahvaz is an industrial city with average highs of around 46℃ during July, its warmest month. The city's record high is 54℃, making it one of the world's hottest cities during the summer. Frequent sand and dust storms and an absence of rain from July to September mix with its sky﹣high temperatures.

    Kuwait City

    The wealthy capital of Kuwait is another competitor for the title of the world's hottest summertime city with average highs of over 45℃ from June to August. Nightfall brings little respite（缓解）, with after﹣dark low temperatures often over 30℃ during the summer months. Kuwait City's record high is 52℃, while it rains on an average of just 19 days per year.

    A study of 27, 000 men showed those skipping (不吃) breakfast were at a greater risk of heart problems. The British Heart Foundation said breakfast helped people resist (抵制) sugary snacks before lunch.

    The men, aged 45-82, were studied for 16 years. During that time there were more than 1, 500 heart attacks or cases of deadly heart failure. However, people who skipped breakfast were 27% more likely to have heart problems than those who started the day with a meal. The researchers took into consideration other lifestyle risk factors (因素) such as smoking and exercise.

    Researcher Dr. Leah Cahill told the BBC: "The take-home message is to eat in the morning when you wake up, preferably within an hour. The results show that something is better than nothing, but it's always better to have something healthy and balanced."

    She said the timing of the meal seemed to be key and waiting until lunch rather than "having breakfast" may be straining (损伤) the body over time. This could be increasing the risk of high blood pressure and fatness which could in turn damage the heart. "Don't skip breakfast," Dr. Cahill suggested.

    Victoria Taylor, an expert with the British Heart Foundation, said: "These researchers only looked at men aged over 45, so we would need to see further research to prove that breakfast has the same effect on the heart health of other groups of people. What we do know is that a healthy breakfast can make that mid-morning biscuit less tempting, as well as giving you another opportunity to widen the variety of foods in your diet. Cereals (谷类食品) with low fat milk are a good way to start the day. Try a banana or dried fruit on top and you'll be on your way to a fine day before you've even left the house."