Giraffes are beautiful, smart and friendly. They have long legs and necks (脖子). They are so tall that they can grow up over 5 meters (米). So how do they sleep or drink?

    You may think it's difficult for them to sleep, but they have no such problems because giraffes don't often stop for a sleep. Giraffes just need to sleep about thirty minutes a day. When they sleep, they don't always lie down (躺下). They usually sleep for minutes at a time, because it's difficult for them to get up again. And it's a great danger to sleep in the wild (荒野). But the giraffes in the zoo sleep for about 4-6 hours every day. They usually lie down when they sleep.

    Drinking water is a big problem for giraffes because their long necks are too "short". To drink water, they must spread (伸展) their front legs in a difficult way. And in this way, other animals like Africa's big cats can easily hunt (猎食) them. So they usually get most of their water from the trees and flowers. Giraffes don't need to drink water very often. They can even drink no water for months!

    Because of the high price of housing, many of us are living in smaller spaces than we'd like. However, living in small spaces is not that bad. It has some advantages.

    {#blank#}1{#/blank#} It can take thousands of dollars to make a large space look better. Small spaces, however, make decorating simpler and more affordable. Instead of many pieces of large, expensive furniture, you only need a few to make your style. You'll have plenty of money left for other things.

    They're easier to clean. This must be one of your favorite things about living in a small space. The bigger the space is, the longer it takes to tidy up. {#blank#}2{#/blank#}That's why small spaces are welcomed by those who like being surrounded by cleanliness and don't want to spend much time and energy in keeping them that way.

    {#blank#}3{#/blank#} It takes a lot to pay for heating, cooling and electricity, which can also cost much energy. When you compare the electricity bill of someone living in 500 square feet with that of someone living in 3, 000 square feet. the difference can be great, We use less energy and produce less waste when we live in small spaces. {#blank#}4{#/blank#}

    They're easier to show your own style. Have you ever walked into a large home that feels more like a museum than the small home of someone you know? It's usually not the most familiar or welcoming atmosphere. Actually, you want your home to show your personal style. {#blank#}5{#/blank#}

A. They're cheaper to decorate.

B. No one wants to spend hours just cleaning.

C. So it also does good to our beloved Mother Nature.

D. They're money-saving and environmentally friendly.

E. It is much easier to decorate a small home in your own style.

    Beauty sleep is a real thing, researches have shown that people who have enough sleep look more attractive (有魅力的) to others.

    A few bad nights are enough to make a person look especially "more ugly", their sleep experiments show.

    The researchers asked 25 university students to join in their sleep experiment. They were asked to get a good night's sleep for two nights.

    A week later, they were asked to sleep for only four hour every night for two nights in a row. The researchers took make—up free (素颜) photos of the volunteers after both the good and the bad sleep.

    Next, they asked 122 strangers to have a look at the photos and judge (评价) them on attractiveness, health, and sleepiness, as well as asking them: "How much would you like to make friends with this person in the picture?"

    The strangers were good at judging whether the person they were looking at was tired, and if he was sleepy, his attractiveness score would be low.

    The strangers also said they wouldn't want to socialize with the tired students. The researchers say this is natural for people. An unhealthy-looking face makes people run away. In other words, people don't want to hang around with people who might be ill.

    Dr Brewer, an expert at the University of Liverpool said: "Judgment of attractiveness is often unconscious (无意识的), but we all do it, and we are able to judge on even something small like whether someone looks tired or unhealthy. This study is a good reminder of how important sleep is to us."

    What's a spacewalk? Any time an astronaut gets out of a spacecraft(航天器) while in space, it is called a spacewalk. Astronauts go on spacewalks for many reasons. For example, experiments can be placed on the outside of a spacecraft. This lets scientists learn how being in space affects(影响) different things. By going on spacewalks, astronauts can also fix things instead of bringing them back to the earth to fix.

    When astronauts go on spacewalks, they wear spacesuits to keep themselves safe. Inside spacesuits, astronauts have the oxygen(氧气) they need to breathe and the water they need to drink. To keep the astronauts and the spacecraft safe, the astronauts must leave and go back to the spacecraft through a special door. When on a spacewalk, astronauts use safety tethers to stay close to their spacecraft. Tethers are like ropes, connect the spacewalkers with the spacecraft. They keep astronauts from floating(漂 浮) away into space. Another way astronauts stay safe during spacewalks is by wearing a SAFER. SAFER is worn like a backpack. It helps an astronaut move around in space.

    How do astronauts train for spacewalks? One way is by going for a swim. Floating in space is a lot like floating in water. Astronauts practice spacewalks underwater in a huge special swimming pool. For every one hour they will spend on a spacewalk, astronauts need to train seven hours in the pool. Another way astronauts practice for a spacewalk is by using virtual reality(虚拟现实). It looks and feels just like a spacewalk.

    Today, only three countries have finished spacewalks independently. They are Russia, the United States and China. The first person to go on a spacewalk in the world was Alexei Leonov from Russia. Zhai Zhigang is the first Chinese astronaut to go on a spacewalk. The world record of spacewalks is held by Russian astronaut Anatoly Solovyev. He has been on 16 spacewalks and spent more than 82 hours outside in space.

A tornado (龙卷风) is a kind of strong storm with air which moves in a circle quickly. They can move over 200 miles per hour and cause a lot of damage (损坏). As they move across the land, they can easily pick up cars, trucks, and even houses, and then throw them very far. It is important to find a safe place if a tornado gets close.

A safe place could be a basement ( 地下室) or the lowest floor. If you are in a home without a basement, try to find a first-floor bathroom or a small room without windows in the middle of your house. You should curl up (蜷缩) into a ball and cover your head and neck with your hands.

But there are some people who actually want to get close to tornadoes. They are scientists who want to learn more about tornadoes. One of the best ways to do this is to get as close as possible to the tornado. They use special tools to measure (测量) what is happening in and around a tornado.

One special tool is called a tornado probe ( 探测仪). Inside the tornado probe, there are sensors (传感器) to measure wind speed, temperature, pressure, and direction.

Some probes even have cameras, so the scientists can see and understand what it's like to be in a tornado.

To be able to get these measurements, the scientists have to get a tornado probe near or into a tornado. Scientists will try to guess where a tornado will go next. Then they drive to that location and put down the probe. If they do not guess correctly, they pick up their probe and try another place. If they are right, the tornado will go near or even right over the probe. Then they take all of the measurements

from the probe and use them to predict where future tornadoes may form (形成) and travel. And they can give people some warning to keep away from a dangerous tornado.

Are you interested in robots? If so, try out robot Little Q at our science center from August Ist to August 6th. Little Q is a cute robot with a round head, two big eyes and two long legs. It's like a big toy that our children will love.