Many things around us may affect our feelings and moods, such as colors, weather, news and the environment. It is very important for us to be in a good mood. If we are in good spirits, we can study or work better. So we must learn to take care of ourselves and stay in a good mood. Here are some suggestions：

①Exercise and relax every day.

②Remember to eat healthy food and have a good sleep.

③Don’t keep silent. Talk with your friends, parents or teachers often. Tell them about what you think and how you feel. Try to get help from them.

④Get help from newspapers, books, TV or the Internet.

⑤Think it over before making an important decision.

⑥Get back to your everyday activities. It will give you a sense of happiness.

The supply of water is causing increasing an uncomfortable feeling to scientists in many countries. In these countries, it is fast becoming an important social and economic problem. The water requirements depend on various facts. An obvious one is the amount needed for household use in baths, showers, washing-machines, toilet and so on. The amount of water used in industry is greater than in the houses. Textile works are major users. A lot of water is also used in agriculture: in irrigation and in the keeping of animals.

In some under-developed countries the daily water consumption* is as low as two or three gallons* while in other countries it reaches 100 gallons a person. As standards of living improve, an increased rate* of consumption must be expected. At the same time, many countries are making a great effort to set up sew industries: to create jobs and get money through exports*. Unluckily, the degree of pollution of the water used in modern industries is often very high and prevents the water from being used again. More water will also be needed in future years for agricultural purposes; with enough water supplies deserts will be transformed and become rich crop-growing areas.

Although the natural supply of water (It comes from fall of rain, snow, etc.) is at present far larger than the world's total requirements, this supply is not distributed and full use cannot be made of it. The conveyance* of water over long distances is too expensive to be practicable, and many of the world's great rivers contains a lot of fresh water which can never be of much real use. For the world's immediate needs, men must now look to new sources of fresh water, and they must develop technologies for recovering fresh water from salt water. Every country is trying to find ways to turn salt water into fresh. In the past, expense had been a difficulty to the widespread use of desalination* plants, but recent technologies has finally made this method reasonable. Some areas, such as Kuwait, are almost totally dependent on external supplies and would be in a dangerous position. Whatever the methods used, scientists are confident that the supply of fresh water will be increased but they point out that the cost will increase correspondingly.

Ludwick Marishane, a South African, was with his friend in Limpopo when they started talking about inventing something to put on your skin (皮肤) so you don’t have to take a bath. Ludwick thought that this was a great idea. He did some research on the Internet, and he found some surprising facts.

About 2, 000, 000 people around the world haven’t got clean water. This is a huge problem because dirty water can create illnesses. One of them is trachoma: 8, 000, 000 people all over the world get trachoma every year. They wash their faces with dirty water, get ill and even go blind. To stop trachoma, people don’t have to receive expensive medical care. They have to wash their faces with clean water. That’s it.

Ludwick started thinking. He wanted to make something to help people in parts of the world where it’s difficult to find clean water. He did more research on the Internet, and he did more thinking. Ludwick had a plan. He wanted to make a gel (凝胶) for people to put on their skin so they don’t have to take a bath. When he was at university, he never stopped thinking about his invention. He started to talk to other people about it, and three years later the dream came true. He made the gel and called it “DryBath”.

Ludwick is the winner of lots of prizes. People call him “one of the brightest young men in the world”. He is happy about his success. DryBath is helping people to be healthy. And DryBath also helps to save water. That’s important in many parts of the world, where it’s difficult to find clean water. Now he wants to invent other things and also wants to help other young people to become inventors.