The skin is an essential part of your body and its largest organ. You have three layers (层) of skin which act as a barrier against disease, poisons and the sun’s harmful rays. The functions of your skin are also very complex: it keeps you warm or cool; it prevents your body from losing too much water; it is where you feel cold, heat or pain and it gives you your sense of touch. So as you can imagine, if your skin gets burned it can be very serious. First aid is a very important first step in the treatment of burns.

Causes of burns

You can get burned by a variety of things: hot liquids, steam, fire, radiation (by being close to high heat or fire, etc. ), the sun, electricity or chemicals.

Types of burns

There are three types of burns. Burns are called first, second or third degree burns, depending on which layers of the skin are burned.

• First degree burns

These affect only the top layer of the skin. These burns are not serious and should feel better within a day or two. Examples include mild sunburn and burns caused by touching a hot pan, stove or iron for a mordent (熨烫熨斗).

• Second degree burns

These affect both the top and the second layer of the skin. These burns are serious and take a few weeks to heal. Examples include severe sunburn and burns caused by hot liquids.

• Third degree burns

These affect all three layers of the skin and any tissue and organs under the skin. Examples include burns caused by electric shocks, burning clothes, or severe petrol fires. These burns cause very severe injuries and the victim must go to hospital at once.

Characteristics of burns

First degree burns

• dry, red and mildly swollen

• mildly painful

• turn white when pressed

Second degree burns

• rough, red and swollen

• watery surface

• extremely painful

Third degree burns

• black and white and charred

• swollen; often tissue under them can be seen

• little or no pain if nerves are damaged; may be pain around edge of injured area

Have you seen Avatar(《阿凡达》)? It’s a popular 3D movie, and you may have to wear 3D glasses to see it. The 3D glasses make the images (图像) from the movie look as if they were coming straight towards you.

More and more 3D movies are coming to theaters. Some say that 3D TV sets will come into our homes in the near future. 3D technology can make TV and movies are more exciting. However, people with eye problems may get headaches if they spend too much time watching 3D movies. Why?

When we look at an object (物体), each eye sees it at a different angle (角度). Our eyes send the two images to our brain (大脑), and the brain puts them together. 3D technology uses two film projectors (投影机). One projects a left-eye-image and the other projects a right-eye-image. 3D glasses allow us to see a different image in each eye. So, when we are watching a 3D movie, our brain can’t put together the images sent to our eyes. The brain needs to work harder at “reading” the images. That makes it easier for people with eye problems to get dizzy (头晕的) or have headaches. A famous eye doctor said if your eyes can’t focus (聚焦) on the same object at once, you will have trouble watching 3D movies.

TEENAGERS lead an exciting life in high school, making friends and dreaming about the future. However, as all young people know, teenagers have plenty of worries too.

Do you know what British teenagers worry about most? A survey by the UK’s Department of Health shows that the top worries are losing weight (减肥) and fitting in (适应). Over 100,000 teenagers took part in the research.

Losing weight is a big concern among teenagers. This may be an effect of famous people with perfect bodies around them.

Adolescence is a physically and emotionally difficult time. Teenagers want to feel good about their bodies.

It’s also important for them to be accepted. Many teenagers were picked on (作弄) in high school. “Who should I eat lunch with?” “Who should I hang out with?” “Will I be accepted?” These questions are troubling many UK teenagers, according to the survey.

It’s interesting to see that family background has an effect on teenagers’ worries. Teenagers from low-income families worried more about losing weight and bullying (欺凌弱小). Teenagers from higher income families were more likely to worry about fitting in and peer pressure (同辈压力).