There are many kinds of 1. transportation now. Which one do you like best, by train, by bus or by plane? Now let's look at these three kinds of transportation. 2.The fastest way to travel is by plane. If you want to save time, 3.乘火车是最好的选择. A plane ticket can also be easier to book, and there are 4.(hundred) of planes leaving half an hour to everywhere. But it is much 5.(expensive) than traveling by train or by car. Many people prefer to traveling together by train. Because the train is cheaper than the plane and you can see the beautiful scenery out of the windows. But sometimes people are very noisy on the train. And it's very small and crowded inside the train. Taking a car is great. You can feel freer in your own car and you can move quickly from place to place at any time you like. 6.But sometimes you may be late because of the heavy traffic  .You have to pay for a car park and petrol . Cars are less comfortable than trains. You can't sleep or relax when you drive. Cars pollute the air more than trains, too.

    Do you know why different animals or pests(害虫) have their special colors? Colors in them seem to be mainly used to 1 themselves.

    Some birds like eating locusts(蝗虫), but birds cannot 2 catch them. Why? It is because locusts change their 3 with the change of the colors of crops. When crops are green, locusts look 4 But as the harvest time comes, locusts change into the same brown colo 5 crops have. Some other pests whose colors are 6 plants are easily found and eaten by 7 So they have to hide themselves for lives and appear only 8 

    If you 9 animals' life, you'll find the main use of colors is to protect 10 Bears, lions and other animals 11 quietly through forests. They cannot be easily seen by hunters 12 their colors are much like the trees.

    Colors are useful not only on the land, but also in the 13 A kind of fish can 14 （液体) when they face danger. The liquid spreads over quickly, so they cannot be found by their enemies and can quickly swim away. That is 15 they can live safely though they are not strong at all. So colors are really useful to animals.

    Some days, don't you think, "Wouldn't it be nice if the laundry would just do itself?” Self-cleaning clothes may sound crazy. But Australian researchers have found a way to make something like this possible!

    A team at RMIT University in Melbourne, Australia, found a way to put special nanostructures (纳米结构) into clothing, which can then clean the clothes. When sunlight hits the nanostructures, they break down the dirt and stains (污渍) that don't belong on your clothes.

    The nanostructures don't break down the actual clothing because cotton and the other clothing materials are too strong to be broken down. According to CNN, the researchers cover the clothing in a solution made of silver and copper (铜) nanostructures. All it takes is 40 minutes of sunlight and your clothes will look as good as new.

    So if you spill on yourself during lunch, you can step outside for a walk, and it will be clean by the time you go inside. It not only makes your life easier, but it can also be good for the environment.

    According to the US Department of Energy, the average load of laundry uses about 25 gallons (about 94 liters) of water. Water is a very important resource, so using less of it to wash clothesis better for the environment. But one of the scientists at RMIT University knows more needs to be done.

    “There's more work to do before we can start throwing out our washing machines,” said Dr Rajesh Ramanathan, “but this is a strong foundation .”

    So what's the next step? Ramanathan wants to either start selling the solution by itself or convincing clothing makers to treat the clothing with the solution while clothes are being made.

    What do Napoleon, Clinton and Wang Nan have in common? They are all left-handed.

Today about 15% of the people are left-handed. But why are people left-handed? The answer is the way the brain (大脑) works. The brain has two halves—the right half and the left half. The right half controls (控制) the left side of the body, and the left half controls the right side of the body. So right-handed people have a strong left brain, and the left –handed people have a strong right brain.

    The two halves of the brain are about the same size. But each side controls different things. The left side controls language, Math and logic (逻辑). When you remember new words, or when you put things in order, you use your left side.

    The right side of the brain controls color and music. It is also good at recognizing (认出)faces. This does not mean that all artists are left-handed and all accountants (会计师) are right-handed. Some right-handers have a strong right brain, and some left-handers have a strong left brain.

    One day, you open the fridge and find some moldy (发霉的)food. But before you can throw it away, your mother stops you. She doesn't want to waste food. She cuts off the moldy part and eats the rest. Is it safe to do this?

    Mold (霉菌)can grow on almost all kinds of food. Mold is usually green, white, black or grey. Mold makes food soft and changes its color. Moldy food tastes quite bad一一and it's not safe to eat.

    If you find mold in soft food, just throw it away. Soft food, such as bread, tomatoes or hot dogs, usually contains water. This allows mold to easily grow below its surface. Bacteria (细菌)can also grow along with it.

    But it's easy to remove mold from hard food. The mold can't grow very deeply inside this kind of food. According to the BBC, you should cut about 2.5 cm around and below the mold to remove it. It's OK to cut the moldy parts out of hard food and eat the rest. But if the food is completely covered with mold, you should still throw it away.

    Most kinds of mold are bad for us. But some kinds of mold can be used to make food. For example, penicillium (青霉菌)can be used to make many types of cheeses, such as blue cheese. These cheeses are safe to eat--and they're quite delicious as well.