Teeth are very important for our health. They will be our friends for the whole life. So we should learn to protect (保护) them at a very young age.

First, we should eat right. Don’t eat too much candy or drink too much cola, or our teeth will go bad easily.

Have more cheese, milk and yogurt (酸奶) to make teeth strong.

Eat more vegetables and fruit to help clean teeth.

Second, we should remember these numbers.

2/Day   Brush your teeth at least (至少) twice a day: in the morning and before bedtime.

2-3 Minutes Brush for about two to three minutes every time.

3 Months   Get a new toothbrush every three months.

6 Months   Go to the dentist every six months for a check-up.

Paper was invented by a Chinese man called Cai Lun almost 2,000 years ago. It didn’t spread to Europe until the year 1100. And four hundred years later, a German discovered that he could make the best paper from trees. After that countries rich in forests, such as Canada Sweden, America, and Finland became the most important ones in paper making.

The common uses for paper include newspapers, magazines and books. But do you know that paper can be used for keeping warm? For example, in Finland, the farmers wear paper boots to keep their feet warm in the snow. And even houses can be insulated from heat or cold with paper.

However, we have to understand that paper still comes from trees now. If we keep on wasting so much paper, there will not be any trees left on the earth some day in the near future. Every day people throw away about 2,800 tons of paper in the world, which means that we are cutting down nearly 48,000 trees every day. The fact is that it takes more than 10 years for a tree to grow.

As for this problem, we can do many things in daily life. We can use both sides of every piece of paper. We can make useful things out of used paper. We can use china or glass cups instead of paper ones. When shopping, we can use fewer paper bags and reuse them if we have some.

In short, we should keep a balance between using paper and protecting trees, and do it now before it is too late.

Do you enjoy eating hamburgers, hot dogs, French fries and chips? Do you like soft drinks, candy and ice cream? If your answers are “yes”, please take care. They are junk food! What is junk food? Junk food has lots of fat, salt and sugar, but few nutrients(营养). Most scientists say junk food is unhealthy. Junk food has been popular(受欢迎的) in the world for many years. Why? First, it is cheap to make. Second, it is quick and easy for people to eat. Third, most junk food has food additives(添加剂), so it looks and tastes better, and people can keep it for long time. Junk food is bad for health. Eating too much junk food may bring some health problems.

It's OK to have junk food now and then(有时). How often should you have it? If you are too fat, you should eat little junk food. If you are not overweight, you can have some after you have enough milk, fruit, vegetables and bread.