2 . Bad breath (口气) usually brings problems when you talk to others in life. It will make people around you feel bad and stay away from you.

What causes bad breath? If you don’t brush your teeth often, germs (细菌) will live in your mouth and between your teeth. It may make your breath smell terrible. Smoking (吸烟) and drinking can also make breath become bad. When there’s something wrong with your body, you may find that you talk with bad breath.

How can you stop bad breath? Here is some advice. It’s necessary for you to use some mouthwash (漱口水) or clean your mouth with water after meals. It can stop germs from staying in your mouth and between your teeth. Brushing your teeth at least twice a day is also a good way. You should brush your teeth for more than two minutes each time. Never stay up late at night, or you may get a sore throat and it may cause bad breath. You’d better not eat food like onions or anything with special smells before meeting others.

If you don’t want to have bad breath, make sure to have good habits in life. You’d better keep away from drinking and smoking. Looking after your teeth and mouth well can help you keep fresh breath all the time.

4 . Oil becomes more expensive and difficult to find. It’s becoming less and less, too. Scientists are looking for other energies, including solar (太阳能), wind and even nuclear (核能) power.

Solar boards (板) catch energy from the sun and turn it into electricity. One of the world’s largest solar power stations is in Germany. What’s more, solar energy produces no waste.

Wind, the fastest growing kind of energy, is another way of collecting energy from the sun. As we all know, Holland is famous for its wind electricity. And it’s also called Windmill Kingdom (风车之国).

Nuclear power produces electricity more cheaply with no carbon (碳) waste. And more countries join the nuclear group. China has built twenty-two nuclear power stations, too.

6 . Each year, hundreds of people climb Mount Qomolangma. Most of them do it to achieve a personal dream. But for some, they push themselves up the mountain for other purposes.

On September 24, 2021, Guo Yongjie and the other seven members of a team set out at a height of 5,800 meters. They reached a height of around 6, 200 meters several hours later. This was the second time the Chinese team had climbed Mount Qomolangma in 2021, following their first trip in August.

“Desideria himalayensis,” Guo cried as soon as he saw a plant. He took pictures of the plant from all directions and recorded its height and location right away. It was the first plant they found at a height above 6,000 meters. What made Guo more excited was that some of the siliques (角果) of the plant had divided, which meant the team had a chance to collect its seeds (种子).

To do research, a complete seed sample (样本) needs at least 2,500 seeds. However, since seeds are scarce at high points of Mount Qomolangma, it is hard to collect 2,500 seeds. So the team could only try to collect as many as possible.

In July 2022, after being kept in very low temperatures for nearly a year, the seeds collected on Mount Qomolangina were taken out to test if they were alive. And soon all the seeds germinated (发芽). It means that China has successfully collected and kept those valuable seeds.

A seed carries the hope of life from the moment it comes into being. For China, those seeds have brought more hope to its plant protection.

7 . Blood transfusions（输血）have become a real life saver in modern medicine. But not so long ago, blood transfusions were dangerous and killed as many people as they saved. That is, until 1901, when an Austrian scientist discovered that humans do not all have the same blood type. His research showed that humans, in fact, have one of four blood types A, B, AB and O.

Before the discovery of the four blood types, it was believed that you could give the blood of any person to any other person. Giving a person the wrong type of blood often leads to death because the two different blood types fight each other. When giving a blood transfusion, doctors need to know the blood types of the donor（输血者）and the recipient（受血者）.

No matter where you live on this planet, your blood will fall into one of the four types. Some blood types are rarer than others. In European cultures, the most common blood type is O. Among Asian populations, the B blood type is common, while it is very rare in European populations.

People with type O blood are “universal（万能的）donors”. Their blood can be given safely to people from any of the other three groups. People with type AB blood are “universal recipients”. They can receive blood from any of the other three groups.

8 . From The Vikings

Now let me tell you something about Vikings.     1     and lived a peaceful life in towns. Many years later scientists discovered some important towns and moved the towns into museums.

    2     Some Vikings lived with their families on farms. But many lived in towns.     3     Towns were often near the sea or a river.     4     Town was also an important place for people to buy and sell different objects,     5     Please read The Vikings for more information.

10 . Water is important for our body and health. It is important because almost all parts of the human body have water. And about 60%-70% of our body is made from water. ①If there is no enough water, our body _________ work properly. ②We can get it through several ways, such as having fruit, vegetables, tea and milk. How much water do we need every day? It is different every day. It depends on our daily activities and the temperature of the day. Generally speaking, an adult needs about eight cups of water every day. ③But when we do some exercise or when the temperature is high, __________.