Cola is bad for our health. Why? Cola is sweet, because it has sugar (糖). Too much sugar can let us get fat. Drinking one bottle of cola each day can make us get fifteen pounds (磅), we can’t eat much healthy food, such as fruit.

Drink water, please. Water is very important to our body. It makes us feel good. We get water from ▲     . But we should also drink enough water every day. If you don’t like to drink water only, you can put a little fruit juice into it.

The popularity of extreme sports (极限运动) is increasing in recent years, especially among young people. Most people do not experience much risk in their everyday life, so here are some sports that can satisfy their need for excitement.

Do you know the numbers 0—9 well? They are numbers in Arabic numerals. People use them to mark numbers now. But it’s not the only number system that people use.

About 2, 500 years ago, people in Rome used their bands to count. In Roman numerals, two fingers means 2, three fingers means 3, you can keep your four fingers close on one side and your thumb on the other side. If you want to say five, you can keep your four fingers close on one side and your thumb on the other side. Make each of your hands be five, then you’ll have ten. So in Rome, the numbers are ‘I, Ⅱ, Ⅲ, IV, V, VI, VⅡ, VⅢ, IX, X’ ” Also, “L” means fifty, “D” means five hundred and “M” means one thousand. But there is no zero in Rome numerals. Today, few people use them because they are difficult to write and count. But we can still see them on some watches and clocks.

Today, most people use the Arabic numerals. They are easy to remember and write. They help people to count things every day. In fact, Indians first created and used the Arabic numerals. In the late 8th century, people in Arabic countries learned about them. Then the Arabic people took them into Europe. So people in Europe called them Arabic numerals. Today, people around the world use Arabic numerals and they help a lot.