Ladies and gentlemen, I returned to this year in a time machine. In the year 2500, we are able to travel through time to any year in the history of the earth. This year is your last chance your lifestyle to save the earth.

    Beginning in the middle of the 20th century, a few people were worried about polluting the earth's water and air, but most people did not change their way of life. Instead, they continued to pour(倒) dangerous chemical(化学物品) and other waste into lakes and seas, to drive more and more cars and trucks, and to cut down trees.

By the year 2200, the earth's water was completely polluted. People could no longer drink water, and they had to use other types of liquids(液体). Scientists said that in the future there might be too many people on the earth. But not enough was done.

So by the year 2300, there were so many people that food became scarce. There was no water to grow food and all of the fish in lakes and seas died because of pollution. Terrible wars broke out between the rich and the poor. Scientists were working very hard to find another planet in space where humans could live.

By the year 2400, the air was too polluted for humans to breathe. So we had to leave the earth. But only the rich were able to leave. Where did we go? Nowhere. And everywhere. You see scientists did not find another safe planet, so now we must travel around the universe in our space ships. We are still looking for a place to call our home.

    So it is up to you to change history. There is still hope. You must change your lifestyle now, before it is too late.

    Wouldn't it be funny if your mum said to you, "It's time for bed, honey. It's almost November!" Well, if you were a baby bear, your mother might let you know it's time to go into a deep sleep around October.

    That "deep sleep" is called "hibernation (冬眠)". When it gets cold, bears have to go into hibernation. By taking this long sleep, they can get through the cold months when the food, like berries (浆果) and nuts, cannot be found easily.

    Have you ever heard someone say that they are as hungry as a bear? Bears need to eat a lot of food before hibernating. They eat so much that they may put on forty pounds of fat in a week. During the winter "bears will live off the fat stored in their bodies. Bears are able to do that because their bodies use a lot less energy during hibernation. Their heartbeats slow down, their breathing slows down, and their body temperature drops.

    If you were going to sleep all winter, wouldn't you want to be in a safe and protected place? That is what a bear wants, so it looks for a cave to sleep in. It makes a bed using grass, leaves and twigs (嫩枝). The bear usually starts to hibernate as early as October and doesn't wake up until April or May. By the time the bear wakes up, it will have lost much of the fat. But spring time will bring much food to enjoy until it is time to hibernate again in the autumn.

    Many years ago, most of our earth wascovered with blocks (块) of ice. These iceblocks were as tall as high buildings in modern cities. Most of the ice was inthe northern part of the world. Then the ice blocks started to move south. Coldand rain came with the ice. Animals had to move. At last, the ice began to melt(融化). After half a million years, most of it melted.More than half of the earth became covered with water. Theclimatebecame much warmer. Things began to grow. The earth began to look the way inwhich it looks today.

① Animal behavior is an interesting and attractive study. Scientists research the ways animals use to look for food. They study how animals protect themselves from their predators, and which animals kill other animals for food. All of this helps us understand how useful animals can be.

② Each country or culture raises some animals for food. In the United States, people mainly eat meat from cows, chickens and pigs. In some other countries, people might raise sheep or buffalo for meat. These differences come in part from weather and other environmental conditions (状况). People around the world eat all kinds of fish and shellfish from oceans and rivers. In some countries, people don't always choose some animal groups, such as dogs, for food while in other countries such animals may become people's favorite food.

③ In West Africa, animals provide humans with more than food. They have been helping people do daily work for thousands of years. Horses, oxen, and other work animals pull heavy things. Elephants, camels and other animals carry people and things from place to place. Carrier pigeons (信鸽) have been used to send messages.

④ People also receive health benefits (利益) from animals. For example, dogs and cats can help calm people down. This is helpful for people fighting illnesses. Animals can also reduce stress, helping people to draw their attention to learning new information, such as reading. When people are walking their dogs or horses, it encourages exercise.

⑤ Animals and humans share space on Earth, so keeping a healthy relationship with animals around us is in our best interest.

Hello! We are students from Thailand, and we want to save the elephants. {#blank#}1{#/blank#}Our first flag had a white elephant on it. This is a symbol of good luck.

{#blank#}2{#/blank#} They can play soccer or music. They can also draw very well.Elephants remember well. They can walk for a long time and never get lost.

{#blank#}3{#/blank#} People cut down many trees so elephants are losing their homes.People also kill elephants for their ivory. Today there are only about 3,000elephants(over 100,000 before).

{#blank#}4{#/blank#} We must save the trees and not buy things made of ivory. Remember that March 13th is Thai Elephant Day.