What are you going to do if you are in a burning building？How will you escape？Do you know how to save yourself？ Please read the following passage.
    Escaping a fire is a serious matter. Knowing what to do during a fire can save you life. It is important to know the ways you can use and show them to everyone in the family, such as stairways and fire escapes, but not lifts.
    From the lower floors of the buildings, we can use windows. We should learn the best way of leaving through windows with the least chance of serious injury.
    The second floor window is usually not very high from the ground. An average person, hanging by the finger-tips will have a drop of about six feet to the ground. It is about the height of an average man. Of course, it is safer to jump out in a right way than to stay in a burning building.
Windows are also useful when you are waiting for help. Be sure to keep the door closed, or smoke and fire may be drawn into the room. Keep your head low at the window to be sure you get fresh air rather than smoke that may leaked（渗）into the room.
On a second or third floor, a person can escape through a window that open onto a roof. Then from the roof drop to the ground. Dropping onto cement（水泥）might end in injury. Bushes（灌木丛）and grass can help to break a fall.

    Noise pollution is doing much harm to our health now. Noise, in fact, is unwanted sound and is a kind of invisible (无形的) killer. More and more students enjoy listening to music very much. When they listen to MP3 players, they like to turn up the volume (音量). Some people love listening to loud music. Furthermore, while watching TV, they keep the volume up. But they haven't realized that the noise is weakening their hearing. In fact, the noise not only influences each member in the family, but also makes a difference to the comfort of neighbors.

Noise pollution is a source of increasing misery (痛苦) to people in our society. If people are often disturbed by it, they may feel uncomfortable or upset. What's worse, the noise can make people mad sometimes. If a worker works in a printing factory for too long, his/her hearing loss is much faster than a common person working in a quieter environment. So everybody must pay more attention to noise pollution. Generally speaking, the following four types of noise should be watched out for:

    ◆Noise in the street

    ◆Construction site (建筑工地) noise

    ◆Noise at work

    ◆Transportation noise

    I think the local department (部门) should take measures to control the noise levels, but it's everybody's duty to keep a quiet environment.

    When some plates(板块)of the Earth move suddenly, an earthquake happens. Many earthquakes begin under the sea. Earthquakes may happen anywhere on the Earth. They often happen near the mountains.

    During an earthquake, the shakings make rocks rise suddenly and even crack(断裂) open. Houses fall down. People are killed or hurt, and sometimes the whole villages or cities are destroyed.

    Can we do something to keep ourselves safe from earthquakes? Scientists have studied earthquakes and made maps that show the “earthquake belt（带）”. In area of these belts, it's possible for earthquakes to happen. In these areas we should build strong houses to fight against earthquakes.

    In the future, Scientists will be able to tell when and where an earthquake will attack before it happens. They can also tell people what to do and how to deal with it.

    Sometimes it seems that time is flying. Perhaps it doesn't need to feel this way. Our experience of time can be possibly changed. By understanding the psychological (心理学的) processes behind our different experiences of time, we might be able to slow down time a little.

    One basic law of psychological time is that time seems to slow down when we're exposed (接触) to new environments and experiences. The law is caused by the relationship between our experience of time and the amount of information our minds process. The more information our minds take in, the slower time seems to pass.

    It follows, then, that we have different experiences of time in different situations. In some situations, our life is full of new experiences. Our minds process a lot of information and time seems to slow down. In other situations, we have fewer new experiences and the world around us becomes more and more familiar (熟悉的). We become insensitive to our experience, which means we process less information, and time seems to speed up.

    How can we slow down time? Here are two suggestions.

    Firstly, since we know that familiarity makes time pass faster, we can expose ourselves to as many new experiences as possible. We can give ourselves new challenges, meet new people, and expose our minds to new information, hobbies and skills. This will increase the amount of information our minds process and expand (增加) our experience of time.

    Secondly, and perhaps most effectively, we can give our whole attention to an experience-to what we are seeing, feeling, tasting, smelling or hearing. This means living through our senses rather than through our thoughts. For example, on the way home, focus your attention outside of yourself, instead of thinking about the problems you have to deal with. Look at the sky, or at the buildings you pass, traveling among them. This open attitude to your experiences helps take in more information and also has a time-expanding effect.

    To a certain degree, we can understand and control our experience of time passing. It's possible for us to slow down time by expanding our experience of time.

    When you look up into the night sky, you can see the moon. But do you know that you're only seeing one side of the moon? The other side, also known as the far side of the moon, has long been a secret to us. But now, we have a chance to see what's on the far side.

    On January 3rd, China's Chang'e 4 probe(探测器) landed on the far side of the moon. It is the first probe in history to land there.

    Chang'e 4 probe has already done a lot of things on the moon. One of its jobs is to grow plants. Chang'e 4 probe took six living things to the moon. Such as cotton, potatoes and fruit flies(果蝇). The cotton has already started growing. This is the first time humans have grown plants on the moon.

    Chang'e 4 probe also took a lot of pictures of the moon's far side. With these pictures, scientists will learn more about the moon.

    A black hole is a place in outer space with very strong gravity. Gravity is a great force(力量) that shapes the universe. On Earth, gravity makes apples fall from trees. It keeps your feet planted on the ground. The gravity in a black hole is much stronger. It is so strong that nothing around it can get away from it, not even light.

    Black holes are invisible. We can't actually see them because they don't throw back light. But scientists can find them with space telescopes(望远镜)and special tools. The strong gravity makes nearby stars move in a certain way. By studying how the stars move, scientists can find out if they are flying around a black hole. Strange things happen around black holes. This makes black holes a popular subject of science fiction(科幻)stories, although they are very real.

    A black hole forms when a star dies. The star falls in on itself and turns into a very small point. Because of its small size and huge mass(质量), the gravity will be so strong that it will pull light in and become a black hole. Black holes can grow huge as they continue to pull other things in and "eat" them. Many scientists believe that there are super-massive black holes at the center of galaxies, including the Milky Way.

    The idea of the black hole was first suggested by two different scientists in the 18th century: John Michelle and Pierre-Simon Laplace. In 1967, a physicist named John Archibald Wheeler came up with the name “black hole". Studying black holes can tell us many things about our galaxy and help scientists answer questions about the universe.