Every year, 1.5 million kids around the world die as a result of not getting vaccines (疫苗). This is partly because transporting and storing medicines can be a huge challenge in some countries.

    Anurudh Ganesan, 17, knows this firsthand. When he was a baby in India, his grandparents carried him 10 miles to a health clinic in a remote village to receive a vaccine. But by the time they arrived, the vaccines were no longer usable because they had been overheated.

    Vaccines, Anurudh later learned, must be kept cool to stay effective. But refrigerating them requires electricity or ice – precious resources that many developing countries lack.

    Although Anurudh eventually received the vaccine he needed, his experience as a baby and the sad reality that so many other children aren't as lucky motivated him to take action. The high school student invented Vaxxwagon, a portable vaccine-carrying device that generates its own power to keep lifesaving medicines cool as they're delivered to remote areas around the world.

    Anurudh first got his idea for Vaxxwagon in 2014. He read several textbooks to learn everything he could about refrigeration, and then he did research online to learn more about vaccines. Rather than relying on electricity or ice, Anurudh figured out a way to use wheels to power a refrigeration system for about eight hours. The entire rechargeable cooling system can be pulled to areas in need of vaccines by a bicycle, a car, or an animal. Eventually, Anurudh took his design to professors at Johns Hopkins University for advice. Not only did they confirm Vaxxwagon could work, but they offered him funding to help build it.

    Anurudh was rewarded with the 2015 Google Science Fair LEGO Education Builder Award for his invention. Anurudh says his final goal is to start selling Vaxxwagon to relief organizations, so it can be used to help people around the world.

Anurudh, who plans to pursue engineering degree in college, says, “Don't give up on your ideas. But always try to help others with your projects. That's the point of engineering – to help people.”

    The secret to happiness is keeping busy, research has found. Keeping the mind occupied with tasks—no matter how meaningless—keeps off negative emotions, the study found.

    However, the bad news is that humans are seemingly born to be lazy in order to save energy, according to Professor Christoper Hsee, a behavioral scientist at Chicago University.

    In a study, 98 students were asked to complete two surveys. After they had completed the first, they were made to wait 15 minutes to receive the next one. They were given a choice of either handing in the first survey nearby or a more distant location they had to walk to. Whichever option they chose, they received a chocolate bar. It turned out that about two-thirds (68 students) chose the lazy option. Those who had taken the walk reported feeling happier than those who had stayed put.

    Professor Hsee concluded that keeping busy helped keep people happy. He said the findings, reported in the journal Psychological Science, had policy implications (暗示).

    “Governments may increase the happiness of idle (无所事事的) citizens by having them build bridges that are actually useless,” he proposed.

    At the personal level, he advised, "Get up and do something. Anything. Even if there really is no point to what you are doing, you will feel better for it." He added, "Incidentally, thinking deeply or engaging in self-reflection counts as keeping busy, too."

    “You do not need to be running around. You just need to be engaged, either physically or mentally.”

    If you're a cycling lover, you will have to pay a lot of attention to your bicycle and maintain it well, for bicycle parts are exposed to wear and tear (磨损) over time and you have to examine the bicycle to see if there are any signs of wearing such as scratches, dents (凹陷) etc. Sometimes, a part may not work because it has exceeded its life expectancy. Sometimes, you will need to find replacement parts for it to keep up the performance of the bicycle.

    Different parts of a bicycle will wear at different rates so it is very important that you have a basic understanding about the role played by each part. One of the most important parts of the bicycle is the frame. You will need to choose a frame that lasts for a very long time. Of course, you will see some paint scratches after some time. When you're selecting a frame, you have to think about the material. Aluminium (铝) frames will not rust easily, but they have a higher chance to dent. Steel frames will be hard to dent, but you will need to make sure they get a good paint job so that they won't rust.

    Wheels also experience a lot of wear and tear and you should go for a professional seller when you want to buy wheels. There are different types of wheels that you can buy, like Zipp wheels that provide more aerodynamic efficiency (空气动力学效能). Investing in new tyres instead of going for used is a good idea because you will be able to get more use out of it. The same goes for chain as there's a higher chance of a used chain breaking. You may also experience shifting problems. However, some parts of bicycles such as pedals can be used for a long time and you can find different styles.

    Other parts that you can buy used are seats, handlebars and the stem. When you are buying handlebars, you have to see if there are any dents or if they have been bent out of shape. There shouldn't be any cracks in the seat post or the handlebars. There are many shops where you can buy parts, so you will have to check the references to see how customers respond to them before you buy anything.

    Researchers have discovered the first Earth-sized planet. It was first marked by scientists' using NASA's Kepler telescope (望远镜), so it's called Kepler﹣186f. It lies about 500 light years from Earth and goes around its star. The planet is the right distance from its star for water: not too close or not too far. Water is one important condition that scientists guess is necessary for life. So it could have water and possible life. It's called a true Earth cousin.

    "This planet is an Earth cousin, not an Earth twin," said Barclay, who is among a team of scientists reporting on the discovery in the magazine Science this week.

    "It's very exciting to find a planet similar to the Earth," Barclay said. "It's not easy work because things change as we get more measurements."

    Scientists don't know anything about the air of Kepler-186f, but it will be a task for future telescopes which can study for chemicals that have something to do with life.

    "It's possible for life to live in this planet, but that doesn't mean there is life in it," Barclay said.

    So far, scientists have found nearly 1,800 planets in the universe.

    "The past year has seen a lot of progress in the search for Earthlike planets. Kepler﹣186f is very important because it is the first planet that is the same temperature and is almost the same size as Earth," scientist David Charbonneau wrote in an email.

    Fern loved Wilbur more than anything. She loved to stroke him, to feed him, to put him to bed. Every morning, as soon as she got up, she warmed his milk, tied his bib on, and held the bottle for him.  Every afternoon, when the school bus stopped in front of her house, she jumped out and ran to the kitchen to fix another bottle for him. She fed him again at suppertime, and again just before going to bed.  Mrs. Arable gave him a feeding around noontime each day, when Fern was away in school. Wilbur loved his milk, and he was never happier than when Fern was warming up a bottle for him. He would stand and gaze up at her with adoring eyes.

    For the first few days of his life, Wilbur was allowed to live in a box near the stove in the kitchen. Then, when Mrs. Arable complained, he was moved to a bigger box in the woodshed. At two weeks of age, he was moved outdoors. It was apple-blossom time, and the days were getting warmer. Mr.  Arable fixed a small yard specially for Wilbur under an apple tree, and gave him a large wooden box full of straw, with a doorway cut in it so he could walk in and out as he pleased.

    "Won't he be cold at night?" asked Fern.

    "No," said her father.  "You watch and see what he does."

    Carrying a bottle of milk, Fern sat down under the apple tree inside the yard. Wilbur ran to her and she held the bottle for him while he sucked. When he had finished the last drop, he grunted and walked sleepily into the box. Fern peered through the door. Wilbur was poking the straw with his snout. In a short time he had dug a tunnel in the straw. He crawled into the tunnel and disappeared from sight, completely covered with straw.

    Fern was enchanted. It relieved her mind to know that her baby would sleep covered up, and would stay warm.