【推荐1】Researchers at Brigham found about one in five teenagers now have some degree of hearing damage. The researchers did not say why hearing loss has risen, but other experts have strong suspicions. One likely culprit, they say, is MP3 players.

An MP3 player can be dangerous to hearing when its decibel level is turned up too high. High-decibel sounds can damage nerve endings, called hair cells. If a sound is loud enough, the damage can be permanent. A loud sound can shake the membrane (薄膜) on which the hair cells sit- “like an earthquake”. That shake can break or even uproot hair cells. When that happens, the hair cells are finished. Human ears cannot regrow hair cells. Therefore, when listening to an MP3 player, set a volume limit and avoid exposure to loud sounds.

On the other hand, the loudness of today’s music may not be totally under your control. Music companies have been purposely turning up the volume. It’s a trend called the fight for loudness.

Play a CD from the 1990s. Then play a newly released tune. Don’t touch the volume control. You’ll probably notice that the new CD sounds louder than the old one. Why? Sound engineers who create CDs are using dynamic range compression (压缩), a technology that makes the quiet parts of a song louder and the loud parts quieter. The overall effect of compression is a louder recording.

Many musicians and sound engineers aren’t pleased. They say that compression is driving down the quality of today, s music, making it sound flat and blaring. Gray Hobish, a sound engineer, explains that music should be a combination of loudness and softness. But music companies want to make music louder so it will stand out. That’s important in the competition among recording companies.

What about listeners? Many teenagers listen to music on the go in noisy places and through headphones, all of which reduce sound quality. So young listeners may not notice the poorer quality of modem recordings. “To their ears,” says Hobish, “the music sounds fine. And they are not aware of the hidden threat of the music they are enjoying.”

【推荐2】Why is the human brain so mighty? It has billions of nerve cells to carry out its commands. Without the brain, you would not be able to think, feel, move, remember, or do all the things that make you the special person you are.

At birth, the brains of infants (婴儿) weigh the same. But by adulthood, that changes. The average male brain weighs about 11 to 12 percent more than woman’s brain. But brain weight and size have nothing to do with intelligence. What matters is what’s inside the brain.

Despite its small size (about 3 pounds), the brain is able to receive and send an unlimited number of messages. It does this with the help of the spinal cord, the sense organs, and the automatic nervous system. The brain carries out this task by assigning jobs.

It puts the cerebellum in charge of balance and coordination.

The brainstem regulates heartbeat, breathing, and blood pressure.

And the largest parts of the brain, the cerebral cortex and the cerebrum, control thoughts, feelings, and actions.

The cerebrum is divided into two halves. Each controls the muscles on the opposite side of the body. So, if you usually eat with your right hand and kick with your right foot, then your brain’s left half is said to “dominate”, and you’re right-handed. When the opposite is true, your brain’s’ right half takes the lead and you’re left-handed.

People use both halves of the brain, but the left half is especially good at helping you with words and numbers and helping you read and speak. The right side is better at creative tasks, such as music and art. And your sense of humor develops there.

Each half has four sets of lobes (脑叶). The frontal lobes behind your forehead do lot of the thinking and planning. The parietal lobes toward the back of your head sense pain. And the occipital lobes at the base of the brain allow you to see. The temporal lobes behind your ears store memories of music, taste, vision, and touch.

【推荐3】What Does the Length of Your Fingers Say About You?

Are you the peace-loving type or the ambitious go-getter? Your finger length might be a clue. Take a look at your fingers. Would you believe me if I told you that the length of your fingers in relation to one another can predict your personality? I know that it sounds like one of those silly tests you see on Facebook, but I have to admit that it is exactly correct for me. Here’s how it works.

Look at your three middle fingers of your hand. Is your index finger longer than your ring finger? Is your ring finger longer than your index finger? Or are the two of the same length? Find the situation that best matches your hand and see if what follows is an accurate description of your personality.

Longer ring finger: The Sweet Talker

If your ring finger is longer than your index finger, research shows that you’re likely a charming type, and you can probably talk yourself out of any situation. Others often find this personality type irresistible and will go to great lengths to help you. You’re more likely to take risks, and you’re good at problem-solving. People in this category make great engineers, soldiers and crossword-puzzle solvers.

Longer index finger: The (Over) Confident One       

If your index finger is longer than your ring finger, chances are you are full of confidence—possibly even to the point of being over-confident and proud. You are not necessarily introverted (内向的), but you do enjoy time to yourself, especially when you’re trying to complete a project. You are a dream pursuer who can make things happen, but you may be shy when it comes to taking the first step in a relationship. You are also probably happy with what you have, but you’re always wishing for more.

Index and ring finger are of the same length: The Peacemaker

If your index finger and ring finger are roughly of the same length, you are likely to avoid conflict at all costs and seek to keep the peace in your relationships. You are well-organized, faithful and sympathetic. But deep down under all of that caring and peace-loving, you also have a hot-tempered side that can appear unexpectedly when you’re pushed too far. You will try your hardest to avoid a fight.

How well do these descriptions match your personality? I was surprised at the accuracy in my case, but I’m not going to tell you which one it was!

A．

B．

C．

D．