Bats are the only “flying animals” in the world. They can't see very well. We often hear “as blind as a bat”. Yet they have no trouble flying on the darkest nights and finding their ways round. How can bats fly and see at night? They fly by radar(雷达).

The bat's radar system(系统) works the same way as the radar in ships and planes. As a bat flies through the air, it makes a sound. If the sound hits things, it will come back and the bat's ears will receive the message. In this way the bat is able to know where the things are. Bats go out for food at night. In the daytime they hang in some dark places. Some people think bats are bad animals. In fact they are useful animals.

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.

B

    People often think of the North Pole(北极) and the South Pole as similar frozen(冰冻的) wastelands. They are both places with very cold temperatures and few people live there. However, the North and South Poles are not much alike as people may imagine.

    The North Pole has no land, only thick ice. Temperatures seldom go above 32°F, at which water turns into ice. Most of the time, it stays below zero. In winter temperatures are usually as low as -30°F.

    Although conditions were very poor, people tried for many centuries to reach the North Pole. About 100 years ago, two men, Robert Peary and Mathew Henson, were able to get to this environment full of troubles and difficulties. They reached the North Pole on March 8th, 1909. It was really a hard trip for them.

    There are few things more dangerous than crossing the Arctic(北极圈) on foot. People who stayed there may face many problems: very cold temperatures, sudden storms, and even hunger. Most of the area is uninhabited. Few people can live in such a difficult place.

    People might think that with such low temperatures for most of the year, the ice would be thick and hard. However, this is not true in the Arctic. The movement of the ocean water under the ice may often cause many different changes on the surface. Sometimes the ice breaks into two opening lanes of water(水道) called “leads”. Anyone who falls into a lead can be frozen to death in a few minutes.

Is It Better to Read Books or Listen to Them?

    We often think how fast we learn something depends on how smart we are. If your brain is taking in material quickly, you're clever; if not, well, that doesn't say great things about your IQ. But science shows context (上下文) and technique (技术) actually play a big role in how fast we learn, and even small changes – like the way you use to read – can make a big difference.

    Audio (音频的) books have plenty of advantages: you can enjoy them anywhere, even in the car, and not printing books saves trees. Poor readers also often find them more interesting. But according to the latest research, if your goal isn't to pass the time in traffic, but instead to learn something difficult, you should choose a physical book.

    In a recent opinion piece in the New York Times, psychology (心理学) professor Daniel T.

    Willingham mentioned a 2010 study where 48 students either read or listened to an article about child psychology. Although the students spent the same amount of time with their material and did about the same number of distracting (分散注意力) activities while they absorbed the information, they scored very differently on a 10-item quiz later. Generally, the readers scored 81 percent but while the listeners scored 59 percent. Why does listening vs reading material have such a great effect on learning?

    Willingham explains that first, most of us read more slowly than we listen (especially when pausing and rereading), and when you're trying to absorb new information, slower seems to be better. "About 10 to 15 percent of eye movements during reading are actually regressive – meaning the eyes are going back and re-checking," he explains to TIME. "This happens very quickly…"

    Second, books offer visual cues (可视线索) that help our brains organize and understand new information. Things like chapter breaks, subheadings, and lists help us in making sense of the material and understanding how it fits together. You lose all that when you go the audio way.

    The bottom line is simple: Don't feel shame about passing your time in traffic with an audio book. However, be aware of audio's limitations when it comes to studying, and seriously consider choosing good old-fashioned reading instead.

An invention in front of your eyes

    What is the most important invention of all time? Is it the written word that helps us to record information? Is it the telephone that lets us talk to people from all over the world? Is it the car that lets us travel at great speeds to meet others? Umberto Eco, an Italian writer, thinks it is something quite different. He says the most important invention might be bright in front of your eyes. He is talking about a simple pair glasses.

    Modern eye glasses were invented around 1000years ago. They were more than just a convenient way to read. Before glasses, writers, scientists or teachers who could not see properly had to memorize everything. After about ten years of poor eyesight, they could not remember well enough and could not work. Glasses meant that people could work in their old age.

    People who wanted to remember some information could write it down and read it. Eye glasses are one of the world's greatest inventions and were probably worn by the people who designed the first telephones and cars.