Water is one of the most common substances on Earth, covering about 71 percent of the Earth's surface. Water is the source of life.

It is an important resource for the survival of all life, including inorganic synthesis and human beings, as well as the most important component of organisms. It is a small amount in the air, but it is an important component of the air.

Water is essential for the normal metabolism of the human body. Under normal circumstances, the body expels about 1.5L of water every day through the skin, internal organs, lungs, and kidneys to ensure that toxins are expelled from the body.

Children are 80 percent water, the elderly are 50 to 60 percent, and normal middle-aged people are 70 percent water.

Water plays an important role in our life. It is one of the important material resources that human beings depend on for survival and development. One cannot live without water for a moment.

For the physiological function of the human body, all the chemical reactions that take place in the body are carried out in the water. Metabolism stops without water. People die.

On Earth, where there is water, there is life. All living activities originate from water. About 65 percent of your body weight is water. Among them, the brain contains 75% water, the blood contains 83% water, the muscle contains 76% water, and even the hard bone contains 22% water.

Once human water shortage, the consequences are very serious.

1. When the water shortage in the body accounts for 1% of the body weight, it will cause thirst and affect the thermoregulation function.

2. When it reaches 2%, it will produce a sense of depression and decreased appetite.

3. When it is more than 3%, it may cause inattention, headache, irritability, and even fainting.

4. Exceeding 9 to 12 percent of body weight can be fatal.

Water has many important functions in the body:

1. Water is an important component of cell protoplasm.

2. Water acts as a solvent in the body, dissolving many electrolytes.

3. Water plays a transport role in the body, carrying nutrients, metabolic wastes, and endocrine substances (such as hormones).

4. Water has high thermal conductivity and specific heat, which can be used as a "heat carrier" to transfer heat between the body and the skin surface and help the human body to regulate body temperature.

As a precious treasure given by nature, water has long been a concern for people. The value of water resources lies in the demand for life on earth and the service of human beings, including power generation, shipping, farming, the environment, and other aspects of water.

As we all know, water is an extremely important and active factor in both natural and social environments. Water is constantly in motion, in the human body, in the farmland, and in the factory, making the world full of vitality and vitality, the dirt is carried away by the water, diluted, and purified by nature.

The earth is called a "water balloon". It is estimated by authorities that the amount of water stored on the earth is up to 385 million cubic kilometers.

If these were spread horizontally on the surface of the earth, the earth would become a "water balloon" with an average depth of more than 2,700 meters. Ninety-seven percent of the water on Earth is this kind of seawater that humans can't drink directly.

Fresh water resources are not only in short supply globally but also in extremely uneven regional distribution. By region, nine countries -- Brazil, Canada, China, the United States, and India -- account for 60 percent of the world's freshwater resources.

About 1.5 billion people in 80 countries and territories, representing about 40% of the world's population, are short of fresh water, and about 300 million people in 26 countries are extremely short of water. Even scarier, the world's water-scarce population is expected to double by 2025, with 40 countries and territories facing freshwater shortages.