Traveling（旅行) is one of the most important activities and people were interested in it many years ago. Modern traffic develops(发展) fast, so traveling to different places has become much faster than before.Staying healthy while traveling can make your trip happier. But do you know how to keep healthyduring a trip? The following advice may be useful to you.

    Before leaving

①Wear comfortable shoes, a hat and sunglasses.

②Take some medicine that you need with you. They can be used when you get ill or have other problems.

③Do some exercise for weeks or months before you leave if you plan to do lots of walking or climbing during your trip.

④Prepare（准备） proper (适当的)food. Take bread, biscuits and some fruit for a long time. They don't go bad quickly. Bring meat, fish, eggs, milk and even salads and vegetables for a nearer one.

While traveling

①Be sure not to eat dirty food or bad fruit.

②Have enough time to take a rest during your trip.Itcan help you become more relaxed.

③Tap（水龙头）water is not safe, so drink bottled water and always clean the cover of the bottle.

④Keep food in good condition（状态）. Remember: If you travel with food, keep hot food hot and cold food cold.

    In nature，you may see many insects and animals of different colors．Have you ever wondered why?

Locusts(蝗虫)are super delicious food for birds，but it is not always an easy job for birds to catch them．It is neither because locusts are good jumpers or runners nor because they are smarter than their enemies．The reason is that the colors of locusts change with the colors of crops(农作物)．When crops are young，locusts look green．But when autumn comes，locusts change to the yellow and brown color as crops do．

    Brown bears，tigers and other animals move quietly through forests．They can't be seen easily by their enemies．This is because they have colors similar to the trees．For the same reason．polar bears that live on a land of snow and ice are white．Butterflies and bees living among the flowers are colorful like flowers．Soil insects are mostly dark—colored and they live under the soil in a dark and wet environment．However，insects with colors different from plants can easily be found and eaten by others．So in order to survive ， they have to hide themselves in the daytime and appear only at night．

    Have you ever noticed some even stranger acts? The ink fish in the sea can send out some very black ink when it faces danger．As the ink spreads over．its enemies will not find themselves suddenly in a dark world．At the same time the ink fish immediately swims away．That is how it keeps itself save though it is not strong at all．

    Every day there is less and less space on Earth for rubbish. Yet every day we make more and more rubbish. What can we do? We can recycle some of our rubbish. Recycling means that the rubbish will be made into something that can be used again.

    Recycling helps Earth. And it saves space in rubbish dumps. Half of everything that we put into landfills could be recycled instead. In fact, most things made of paper, metal, glass and plastic can be recycled.

    Paper can be broken into small pieces and made into new paper. Steel and aluminum cans(金属雄)can be melted down(熔化)and made into new cans. The same is true of glass bottles. This can be done over and over again. Recycling doesn't take as much energy as making these things the first time. So we can use less of Earth's fuel resources.

    Plastic can be melted down, too. Then it can be formed into park benches, playgrounds and so on. Some people call plastic the "wood" of the future. Things made of plastic will last about 400 years-even if they stay outside in the weather. No wood can do that!