We have always been interested in the moon. 2000 years ago people already knew it moved around the earth and where it would be in the sky at different times of the year. At that time, everything about the moon was learned by watching it carefully in the sky.

    When scientists could use telescopes to study the moon more closely, their ideas began to change. They could see the moon was made of rocks. Most scientists thought moon rocks would be different from those on Earth. This was because they believed the moon had once been a planet that had been caught in the earth's gravity (引力) millions of years earlier.

    In 1969 moon rocks were finally brought to the earth and studied. Much to their surprise, scientists found that, except for water, the moon and the earth were made of the same things. Once again new ideas were needed for this new information.

    After years of study, most scientists now think that the moon was once part of Earth. They believe very early in its history, maybe 4 million years ago, something about the size of Mars hit Earth. This sent billions of rocks into space around our planet. These rocks slowly joined together and after many years became the moon.

    However, in the future, even though our ideas about the moon may change again, we will still be interested in it.

    My name is Wei Hua and I'm a sporting robot of the 23rd century. I'm clever at high flying exercises. I jump from spaceships and as I fall, I turn, dive, circle and dance until I softly land as close as I can to the finishing line.

    Robot competitions in the 23rd century are truly a popular sport. Fans from all over China watch their hand—held TVs when a competition comes on. Last time I took part in the 78th Olympics and I won the silver medal for my performance. This year I was very proud to be chosen again. I wanted to meet robots from other countries and explore ideas about our sport. However, my programmer fell ill the week before we were leaving. It was very painful for her and I felt very scared. I didn't feel so confident that I would win.

    The day of the competition was rather cold for my legs and my special oil began to freeze. I stopped for a moment(which I shouldn't) before I jumped from the starting place on a little spaceship, then I began my performance. At the correct moment I tried to open my parachute(降落伞)but there was a problem. It only opened a little. I began to fall faster and faster so that I could not turn, dive, circle or dance. My heart stopped beating as I landed heavily on a mountain covered with snow.

    This is why I am writing to you from my hospital bed with two broken legs and a weak head. I did not win anything at the Olympics after all. I need the factory to build me two new legs and an even bigger head. Then I will be able to compete once more. Let's hope for greater success in the next Olympics!

    In traditional Chinese medicine, food is divided (划分) into two types; hot and cold. Both kinds of food affect (影响) your body {#blank#}1{#/blank#} different ways, So, having 57. {#blank#}2{#/blank#} balanced diet is safe and {#blank#}3{#/blank#} (health) for your body.

    Some examples of hot food {#blank#}4{#/blank#} (be) berries, mutton, and ginger (生姜) . If you eat too much of them, {#blank#}5{#/blank#} (certainly) things might happen to your body. You may start to sweat a lot and feel pain in your back, or even grow gray hair! If these things happen to you, you should avoid (避免) spicy food, coffee, or sugar.

    On  {#blank#}6{#/blank#} other hand, too much cold food like tomatoes and potatoes can also cause problems. It may make your hands and  {#blank#}7{#/blank#} (foot) cold. It also makes your body temperature lower.

    Besides what we eat, {#blank#}8{#/blank#} we eat is also important. You should always sit down and chew (咀嚼) carefully. Don't make {#blank#}9{#/blank#} (you) busy with other things, such as watching TV or {#blank#}10{#/blank#} (read) a newspaper. Finally, it's best to eat three meals a day at regular times.

Hello, my name is Li Lin. You can call me Jack. I'm a 14yearold schoolboy. Now, I am studying at a school in the UK. Let me tell you about the fun things I do in this country. 

I like riding my bike in the UK. I can get anywhere on my bike in Cambridge. It's really fun. But riding a bike in the UK is different from that in China. 

First, you have to ride on the left of the road. In China, you ride on the right. When I go to the UK for the first time, I ride on the right of the road. Cars run fast by me. It is terrible(可怕的). 

Second, the UK bikes have lights on them. They have a white light at the front and a red one at the back. You can use them at night and early in the morning. 

Third, in China, bikes usually have a stand (支架). But you can't find them on most of the UK bikes. Why? You can't leave your bike where you want. You have to put it in a bike park. It's a good idea. 

The human spine（脊柱） doesn't just help us stand up straight. Inside the spine is the spinal cord (脊髓) {#blank#}1{#/blank#} The legs and feet send "sense" information to the brain, saying they're hurt or hot, for example. And the brain sends messages to the lower body, telling the legs to walk, dance or sit down. 

When someone's spinal cord is hurt, information about senses doesn't reach the brain from the lower body. And control messages can't make it to the lower body from the brain. {#blank#}2{#/blank#}

Surprisingly, now scientists in Switzerland have given three paralyzed men the ability to walk again. All of the three men had damaged their spinal cords in motorcycle accidents and couldn't move their legs. To help them walk again, a special device (装置) was put directly on the lower part of their spinal cord. 

The scientists controlled the device from a computer. {#blank#}3{#/blank#} In the past, scientists have had some successes with the similar device in the lower spine. Some patients have even trained themselves over months to be able to walk. 

But this research is different. {#blank#}4{#/blank#}Instead, the computer tells the device to send "walking" messages. The scientists use computers to create patterns of movement—like taking a step—that work well with each patient. The patients then choose the pattern they want, and the muscles (肌肉) move in the chosen way. 

Over time, the three men are able to walk on their own, using a special walker with buttons to trigger (激发) each leg. {#blank#}5{#/blank#} The scientists are hopeful that in the future, this technology will allow more paralyzed people to walk again. 

Hello! Do you know how people greet each other in different countries? Let's find out!

In Asia, people often bow their heads. It's a nice way to be polite without touching(接触).

When you meet someone in India(印度), they might say" Namaste." They touch their hands together to show respect(尊重).

In Turkey(土耳其), you might see people kissing an older person's hand and then their forehead(额头). It's a kind way to show respect.

The Maori, who live in New Zealand, have a special way to say hello. They touch noses and foreheads. It's called" hongi."

In Malaysia, people put their hand on their chest(胸部) and nod their heads. It's a friendly way to greet someone.

In the US and some other countries, people often shake hands. It's a common way to say" hello."

Sometimes, friends just smile and say" Hello" or" Hi."A smile can make everyone feel good.

In some places, friends kiss each other on the cheek(脸颊). They might do it once, twice, or even three times!

So, when you meet new people, remember that there are many ways to say" hello" around the world.