If you are riding a bike in foreign countries, you need to know what these traffic signs mean.

1		This sign means “walk”, you can cross the street along with other people.
2		This sign is the “don't walk” sign. It means you should stop to wait for a while until the sign of “walk” is showing.
3		This sign means that there is a bike lane. If you see such a sign, you must use the bike lane.
4		Car drivers and bike riders must come to a complete stop at “STOP” signs.
5		This sign means you are coming to a zebra crossing. You must slow down to allow people in the zebra crossing to cross the street.
6		This sign means parts of the road are rough. Be careful! Rough roads make you fall off your bike.

Florida teen band The Garbage-Men is performing on the stage. The band has five members. They are Jack Berry, Ollie Gray, Harrison Paparatto, Austin Siegel and Evan Tucker. The five teens are making music from waste. The Garbage-Men band's instruments are made from recycled things. The guitars are boxes. A horn(号) is made from pipes. The keyboard is formed from old bottles.

    The band started about two years ago. Jack Berry who was in eighth grade at the time decided to make a playable, home-made guitar. After some trial-and-error(反复试验),                he ended up building it from a cereal box,  a yardstick and toothpicks. After Jack showed his creation to his friend Ollie Gray, Ollie had the idea to form a band using other home-made instruments as a way to improve recycling. “We want to show people there is more to recycling than throwing things away in the bin.” Jack, 16, told TFK. “You can actually reuse materials.”

Last year, the Garbage-Men played at local events, including festivals, farmer's markets. Typically， the teens set up on the street and performed popular songs from the 1960s， including classic Beatles and crowd favorite “Wipe Out”. They talked about recycling and offered tips for how to improve the environment. While they were performing, Jack's little brother Trent, 11, gave out leaflets about recycling and helped sell the band's CDs and other musical products.

The band donated the money from sales to charity. They have raised more than $2,500 for Heifer International. The organization gives farm animals, seeds and agricultural training to people in poor countries to help end poverty and hunger. “It's a good, sustainable-development (持续发展的)charity,” Jack says, “By donating one animal, you help the whole community.”

The band, all tenth graders, tries to play a show every week. They've also played on a Florida radio station. The teens hope to take their shows on the road by touring in other states. “Music is a really good way to get a good message across to people because it's really close.” Jack says. Their instruments may be rubbish, but their message isn't.

The Smallest Life Around Us

    Tiny plants and animals live all around us．We cannot see them because they are so small，but they are everywhere. They live in the soil，in the air，and in rivers and oceans．They grow on mountains and in caves．Some live in the ice at the north and south poles; some live where it is very hot．They are found throughout cities and in the country. They grow on other plants and animals．Some are even living on you，on your skin，hair，and inside your body，in your mouth，nose，and all through your body．

    These tiny plants and animals are called microbes．The word microbe is made from two other words：micro，meaning small，and bios，meaning life．So，microbe means small life．

    Microbes have been on earth for a very long time．They may have been the first forms of life to be alive．Today there are more microbes in the world than all other living things．

    People did not know microbes had existed（存在） long．They were too small for them to see．But people did see many changes in their world﹣important changes．And they did not know what caused them．They saw food that they kept too long change color and begin to smell bad．They saw cuts and wounds grow red and painful and become worse. They saw old plants and leaves and trees crumble apart on the forest floor and disappear into the soil．Such changes were a natural part of the world，but people did not understand them．They did not know these changes were evidence(证据) of tiny plants and animals growing all around them.

    Life in space is much different from life on earth. How do astronauts live in space?

    Eating    In the past, astronauts could only eat small pieces of dried food. But now they are able to eat more everyday food like fruit, vegetables and ice-cream.

    Sleeping    All the people on the ISS（国际空间站）have their own rooms. They should be tied（系）to their beds, or they'll fly away! That seems like a hard way to sleep, but astronauts say sleeping is really not too bad.

    Exercising    This is more important in space than on earth. Astronauts exercise on bikes and other machines（机器）for about two hours every day. That way, they can still be healthy when they get back home.

    Having fun    Astronauts can read books, play cards, listen to music or send emails to their friends and families when they aren't working. Sometimes they just sit and look out of the window. It's also much fun!