Do you and your friends ever talk about your dreams with each other? If you do, you might have noticed something interesting – some of your friends seldom remember their dreams, but some can always describe their dreams so clearly that it seems like they're describing things that really happened to them. What makes those people different?

    The answer is simple. There are two different types of dreamers – low dream recallers（回忆者）and high dream recallers.

    Low dream recallers usually remember their dreams only twice a month. But high dream recallers are able to remember them about five mornings a week. And a new study suggests that activity in a certain part of the brain could have something to do with it, reported The Huffington Post.

    Perrine Ruby, a French researcher at the Lyon Neuroscience Research Center, studied 41 people (21 high dream recallers and 20 low dream recallers) and recorded their brain activity.

    She found that a part of the brain called the temporo-parietal junction (颞顶联合区) was more active in high dream recallers than in low dream recallers – both when they were sleeping and awake.

    This brain area collects and processes（编程）information from the outside world. This means that high dream recallers know more about what's happening around them. For example, when they are awake, they respond (对……有反应) more strongly to hearing their own names, and when they are sleeping, they are woken more easily by sounds and movements.

    By closely studying people's brain activities, Ruby found that high dream recallers have twice as much “wakefulness time” during sleep as low dream recallers do. And it is during these short times of wakefulness that the brain remembers dreams.

    “The sleeping brain is not able to remember new information,” Ruby told The Washington Post. “It needs to wake up to be able to do that.”

    This is not hard to understand. Just try to think of your own sleeping experiences. If you are worried during the night, you are more likely to remember your dreams, but if you sleep well, you will remember little in the morning, and this is because “you never get a chance to remember”, Robert Stickgold, a Harvard Medical School researcher, told The Washington Post.

    Trees are one of the oldest " citizens (公民) " of our Earth. They keep our air clean, reduce noise pollution, improve water quality and provide food and building materials.

    Just like us, trees change a lot as they grow. At 1 to 3 years old, young trees learn how to protect themselves. For example, many trees grow thorns( 刺) to warn animals not to go near. Most young trees have large, deep green leaves so that they can catch enough sunlight and change it into their food and energy.

    When trees are 4 years old, they begin to grow very rapidly and become strong enough to face challenges later in life. At the age of 15, trees become young adults. They grow more slowly and begin to produce flowers and fruit.

    It is not until the tree is 20 to 25 years old that it becomes a real adult. The tree reaches its largest size. The adult tree gives us shade, oxygen and natural beauty; it is also a great place for a tree house, or a place for us to read a book, listen to music and so on. If we give the adult tree proper care, it will go on to live healthily for many years.

    Gradually, trees begin to grow older and older and even die. At this time, they still have their important place in nature. When a tree becomes hollow (空心的) or part of it becomes dead, it provides a home to small animals and is a source of food for many other animals.

    In many ways, the life of a tree is similar to our own life experience. When we are looking at the life of a tree, we learn about that each period of life brings its own form of joy and challenge.

    Enjoy every minute of the life of the trees and take care of the trees!

    Some animals sleep during the wintertime because the weather can be very cold and it is difficult for them to find food. They can sleep for a long time. This kind of winter sleep is called “hibernation”.

    If an animal moves about a lot, it needs food. Hibernating animals do not need to eat much because they are not moving about. Their hearts(心脏) beat very slowly and they also breathe(呼吸) slowly. They find a place that is sheltered(遮蔽的) from bad weather and where they are out of danger. Their body fat(脂肪) keeps them alive and warm.

    Some animals, such as bears, may wake up from their hibernation on warm winter days and then quickly go back to sleep again when they see the snow is still thick on the ground. When the weather becomes warmer in spring, the animals start to wake up and look for food.

    Let's take a look at the cool inventions in science and technology.

Robot-teacher

    Some students in South Korea have new language instructors: the English-teaching robots. The robots help students practise speaking English. South Korea employs many foreigners to teach English. The robot-teachers can help to solve a shortage of English teachers. Can robots replace human teachers one day?

Superhero suit

    Have you ever dreamed of becoming a superhero? There's a real Iron Man suit, XOS 2. The suit provides the power to lift 200 pounds and break the wood easily. It was designed to help the military with heavy lifting. One person in the suit can do the work of three soldiers.

Hard-working robot

    The EMIEW2 robot is a perfect office helper. It can guide visitors to the places they want to go. The three-foot-tall robot can know different human voices and react to instructions. One day, it may work as a receptionist or a guard.

    Pisces is the twelfth star sign. There is a legend about its name.

    Long, long ago, there was a war between gods and a bad monster (怪物). It lasted ten years. One day, the gods were surprised to find that the monster was coming towards them. The goat god Pan shouted a warning and tried to change himself into a fish. One god, Aphrodite, took her little boy Eros and tried to hide among the bushes near Euphrates River. She was the god of love and her son was the god of war. It is said that two fish swam to carry Aphrodite and her child to safety. Some people also believe that Aphrodite and Eros changed into fish themselves and swam away to safety. Later the fish represent Aphrodite and her son Eros.

    As they appeared in the sky, the two fish were tied together by a rope (绳子). Some said that Aphrodite tied the little boy to her body so that he would not get lost as they swam away to safety. That's the story about Pisces.

    In Western countries, some people believe people will share similar characteristics if they have the same star sign. So if you're born between February 19th and March 20th, your star sign is Pisces. It means that you are generous, easy-going and creative.