“An apple a day keeps the doctor away.” Similarly, if we drink a little more water every day, we may find that we need to go to the doctor a lot less often. A healthy diet is made up of water and a great many different kinds of foods. We know that healthy foods like fruits, vegetables and fish, are important as they provide us with energy and fiber, without giving us too much fat and sugar. But why is water important?

The human body needs water to survive. Water is important as it carries poisons and waste out of our bodies. So, doctors advise us to drink plenty of water, much more than the small amount we need to stay alive.

Some doctors believe that water is important for our health in all kinds of ways. They believe that a great many illnesses and health problems start as a result of dehydration (脱水) — a lack of water in the body. Most people are dehydrated at least some of time, although they probably don’t know it. It is surprising to learn that if we feel thirsty, we are already in the first stage of dehydration. In fact, we are advised to drink water before we feel thirsty.

These doctors think that health problems such as headaches, high blood pressure and asthma (哮喘) could be helped if people drink more water. They also believe that drinking more water can help people who are overweight. Water contains no calories so it will not make us put on weight. If we drink water, we will probably drink less sugary soft drinks such as Coca-cola. Doctors also believe that drinking more water may stop people from overeating. They say that many people think that they are hungry when they are, in fact, thirsty. Doctors suggest, therefore, that we eat less food and drink more water. There are still many health problems that cannot be solved by drinking water, so we should not stop going to seeing the doctor completely. However, if we make a decision to drink water every day, we may find that we need to go to the doctor a lot less often.

Are you the kind of person who always keeps a bar of chocolate nearby? Perhaps you feel weak or sleepy without your sweets. If so, you may have a problem that millions of others have: sugar addiction.

Addiction means using a substance or doing an activity over and over again, in spite of its bad effects. Playing computer games, drinking, and eating arc examples of activities that can develop into addictions.

There are four stages (阶段) of behavior that happen during a sugar addiction. Stage one begins with a strong wish for something sweet. This happens because sugar causes the body to produce dopamine (多巴胺). It is a chemical that creates feelings of happiness. In stage two, even after sugar has been eaten, the desire remains and grows. This is because the body becomes less sensitive (敏感) to the effect of sugar over time. So, it is necessary to eat more sugar to produce the positive emotions. In stage three, when a sugar need is not satisfied, the person feels bad. Sugar addicts experience bad emotional symptoms (症状). They also feel physical symptoms, such as headaches, sleepiness, and lack of energy. Over time, a sugar addiction will reach stage four. This is when the worst health effects of sugar addiction can be seen. Unhealthy body weight and depression are examples.

Breaking a sugar addiction can be challenging, but it is important for your health. There are a few things to keep in mind. It’s simple advice you probably have heard before. Eat three meals a day, get enough sleep, and exercise often. Choose healthy sweets, like fruit, and avoid salty snacks. These usually cause people to want to eat sweets. Don’t push yourself too hard. Remember that lifestyle changes happen slowly.

Flying can be fun and exciting, no matter what you choose to do. But have you ever thought about what happens on the plane?

Here are some of the most interesting things that happen.

When you flush a toilet on a plane at an altitude of 30,000 feet, there must be a question on your mind: “Is this about to land on a farmer’s house?”

Take it easy. A plane’s toilets cannot be emptied in the sky. The waste is stored in tanks on board and can only be operated by the ground crew.

However, why is news like “blue ice falling out of a plane” reported? Is blue ice human waste? Stories about blue ice are true but rarely happen. The FAA said some lavatory holding tanks have a blue chemical in them. If a tank leaks high in the air, the water freezes once it hits the outside air, and melts before it lands on the ground.

It’s scary, uncomfortable and spills your drink. But is turbulence something you really need to worry about?

Absolutely not. It’s part of flying, and it isn’t dangerous. Turbulence is caused when two masses of air hit one another at different speeds. Wind, thunderstorms and closeness to mountains are all possible reasons. Despite how dangerous it feels, turbulence won’t crash your plane. Even in extremely rough air, the wing is not going to break off.

If you have traveled by plane before, you may have noticed that every plane window has a round design. This isn’t to make the plane look good. It’s for the safety of everyone on board.

As the airplane flies higher and higher, the outside atmospheric pressure gets lower and lower. In the end, the pressure inside the plane becomes greater than the pressure outside. At this time, windows that can resist pressure are needed.

Square windows can crack. The different pressure inside and outside put stress on the right angles. However, rounded corners help to reduce these stresses by spreading them around the window.