Have you ever rubbed your hands together when they get cold? Why do we do that? We do that for friction. Friction happens when two things that aren't very smooth rub together to make heat energy. The faster you rub two things together, the more friction (and heat) you can make. Let's discover friction!

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    Most people hope to have a memory which helps them succeed in study, work and life. Can memory be improved? Luckily, hundreds of studies in the past 50 years have already given us a definite answer.

    A healthy lifestyle keeps our brain young and memory sharp. First of all, it is necessary to have a healthy diet. Eating more food rich in B vitamins and vitamin E, such as vegetables and lean meat, helps you have a better memory. Doing exercise can keep your brain alive, too. Proper exercise provides much oxygen for the brain. Running, riding a bike, swimming and even walking two or three times a week are helpful. Moreover, getting enough sleep is important. Only when your brain gets a good rest, can it work well. The healthier your lifestyle is, the better your memory will become. But do not expect a sudden change－it takes a long time to make a difference.

    Memory stills help you remember things better. The following three are the most widely used. Chunking is a way of remembering a piece of information by cutting it into small ones. For example, to memorize a ten-digit telephone number 2127983630, you can divide the digits into three groups: first 212, then 798, and lastly 3630. This method is far more effective than remembering a string of 10 digits. Organization means organizing information into groups of the same kind. For example, trees, grass and flowers are plants; tigers, pandas, horses and cows are animals. Imagery is remembering newly learnt information by using your imagination and connecting it with something that you are familiar with.

    However, memory skills will hardly work if you don't understand the information. What's more, only a regular review can make the memory last long. That is why students are always advised to go over what they have learnt and then use it as regularly as possible.

    Human brains are like muscles that needs nutrients and exercise to become stronger. If you make a few lifestyle changes and try some memory skills, you can certainly improve your memory.

    There are many kinds of ants(蚂蚁) in America. One is very strong. People are afraid(害怕) of it and animals are afraid of it, too.

    These ants are often in big groups(群). They eat all the animals on their way. They can kill(杀死) and eat elephants. And they can eat house. Sometimes they can kill people and eat them. When the ants come near, people leave their homes. But people are sometimes happy after the ants pass by (经过), because they can see no insects(昆虫) or snakes(蛇).

    Is there intelligent(有智力的)life on other planets? For years, scientists said "no." or "we don't know." But today this is changing. Seth Shostak and Alexandra Barnett are astronomers(天文学家). They believe intelligent life exists(存在)somewhere in the universe. They also think we will soon contact these beings(人;生物).

    Why do Shostak and Barnett think intelligent life exists on other planets? The first reason is time. Scientists believe the universe is about 12 billion years old. "This is long enough for other planets to have intelligent life," say Shostak and Barnett. The second reason is size—the universe is huge. "Tools like the Hubble Telescope(哈勃望远镜)have shown that there are at least 100 billion galaxies, " says Shostak. "And our galaxy, the Milky Way, has at least 100 billion stars. Some planets going around these stars might be similar to Earth."

    In the past, it was hard to look for signs of intelligent life in the universe. But now, powerful telescopes(高倍望远镜)allow scientists to discover smaller planets——the size of Mars or Earth—in other solar systems. These planets might have intelligent life.

    Have beings from space already visited Earth? "Probably not," says Shostak. "It's a long way away. However, intelligent beings may contact us in other way, such as radio signals(信号). In fact, they may be trying to communicate with us now, but we don't have the right tools to receive their messages. However, this is changing. By 2025, we could make contact with other life forms in our universe and we might help each other."

    When you are waiting on a phone call with a pen in your hand or feeling bored on a train, you may probably doodle(涂鸦). Consultant Graphology(笔迹咨询师)Tracey has studied the most common doodles and their meaning in a new piece of research. Here she shares the psychology(心理学)behind those doodles.

Singapore is a city of different cultures. Walking through the streets of Singapore, you can{#blank#}1{#/blank#} (听到)different languages spoken, such as English, Chinese and Malay. People from different cultures live and work peacefully with each other and share their traditions.

In Singapore, cultural differences are shown in building styles, shops and in many other ways. Take food as an {#blank#}2{#/blank#} (例子), each culture has its own place to sell their traditional food, but there are also the {#blank#}3{#/blank#} (著名的) hawker markets. Different foods are sold in these {#blank#}4{#/blank#} (繁忙的) markets.

And these are very {#blank#}5{#/blank#} (受欢迎的) with Singapore citizens and {#blank#}6{#/blank#} (游客) from around the world. The food is good and very{#blank#}7{#/blank#} (便宜的).

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