The sea is set against the backdrop of most of the earth s water, known as Water Polo 30

The sea is set against the backdrop of most of the earth's water, which is called a water ball.

Choice of absorption is the main reason why objects take on color. In a certain wavelength range, if a substance absorbs an equal amount (referring to energy) of light of various wavelengths passing through it, and the absorption amount is very small, the substance is called general absorption; If a substance absorbs a certain wavelength of light energy significantly, it is said that the substance has selective absorption. When sunlight hits the surface of the sea, some of the light is reflected back and the other part is refracted into the water.

The light that enters the water is absorbed by the water during its propagation. The absorption of light by water is related to the wavelength of the light, i.e., water has selective absorption. Water absorbs light with longer wavelengths significantly, but not with shorter wavelengths.

Red, orange and yellow light are all absorbed at different depths and increase the temperature of the seawater. To a certain depth the green light is also absorbed. Blue and violet light, which have shorter wavelengths, scatter or reflect back on water molecules or other particles when they encounter them.

Therefore, when the sea water is clear and clear, the blue light and purple light that are least absorbed by the sea water in our eyes are reflected and scattered into our eyes, and the sea we see appears blue.

Let's see from what point of view.

If in essence, the Earth is a water ball. This is because the Earth's oceans cover 71% of the total area, while the land covers only 29%.

And now the glaciers at the poles are melting rapidly as the world warms.

Sea level rises.

I believe it won't be long. The sea will cover the entire planet.

I don't know what the landlord asks?

71% of the Earth's surface is covered by water, and only 29% is land, so it can be called a "water ball".

However, the proportion of water is very small in terms of mass ratio, so it is not wrong and more appropriate to call it "earth".

If the volume of ocean water accounts for the total volume of water on the earth, it covers the surface of the earth.

7 out of 10 (correct answer).

Five out of ten. Three out of ten.

Ten of the high bridge nine.

The volume of ocean water accounts for the total volume of water on the earth (Takahashi), which covers the surface of the earth ().

Seven out of ten (correct answer to Qi staring at the case).

Five out of ten. Three out of ten is a cluster.

Nine out of ten.

The fact that the water on Earth comes from the sun sounds like a fallacy. Everyone knows that water h o is a substance composed of two elements, hydrogen and oxygen, and the earth's surface 2 3 or more is covered by water, so the earth is also known as the planet of water, so where does the water on the earth's surface come from? The Earth was born about 4.6 billion years ago in ancient times, and the first prototype of the Earth was created with the formation of the solar system.

Before the formation of the solar system, due to the "supernovae**" in the more ancient period, the "primordial nebula of the solar system" was formed in the position of the solar system, and a large number of cosmic dust Egyptian meteorites gradually formed the planetary system inside the solar system with the influence of gravity. This is how the Earth, as a "rocky planet" in the inner solar system, was born.

One idea is that water was captured from cosmic space when the earth was formed. When meteorites containing water condense to form the Earth, the water is sequestered in the structure of the Earth's internal material. Later, due to the increase in the temperature of the earth, the rotation speed accelerated, and under the action of the earth's self-rotating centricity, the light and lively water squeezed out of the earth's surface and appeared in a state of water vapor.

It then condenses to form precipitation, which thus constitutes surface water. There are also scientists who think that the earth's water comes from comets, because they found that many comets around the earth were originally composed of ice crystals, when the comets enter the earth's atmosphere, they will rub and generate heat, thereby releasing water, after accumulation over time, but there are hundreds of millions of comets from space, and gradually constitute water on the surface.

If the hydrogen received by the earth from the solar wind is separated from the oxygen on the earth to become water since the composition of the earth for 4.5 billion years, the total amount of hydrogen received by the earth is exactly the same as the total amount of global seawater today, according to calculations, the total amount of hydrogen obtained from the solar wind from the composition of the earth to the present day is tons, and the total amount of water in the global hydrosphere is tons, the difference between the two is not more than 10%, and the remaining water may come from comets and so on. The study concluded that the hydrogen in Earth's water comes from the sun.

Scientists point to strong evidence to support this conclusion, which is that the ratio of hydrogen to deuterium in the Earth's water system is about the same as that of the Sun, at around 6,700:1. If this idea is true, then 2 3 of the water on Earth comes from the sun, which will change people's preconceived impression that "water and fire are incompatible".

Mainly brought about by comet impacts. There are free water molecules in space, which eventually condense into water. When the comet enters the atmosphere, it rubs against the atmosphere, and the ice on its body turns into water vapor before descending to Earth.

If the hydrogen received by the earth from the solar wind is separated from the oxygen on the earth to become water since the composition of the earth for 4.5 billion years, the total amount of hydrogen received by the earth is exactly the same as the total amount of global seawater today, according to calculations, the total amount of hydrogen obtained from the solar wind from the composition of the earth to the present day is tons, and the total amount of water in the global hydrosphere is tons, the difference between the two is not more than 10%, and the remaining water may come from comets and so on. The study concluded that the hydrogen in Earth's water comes from the sun.

The first point is that the water on the earth is formed due to some special changes in the entire ocean, and the second point is that the water of the ocean is actually brought by the earth itself, and it slowly produces water from the entire ocean water.

The water on the earth is all groundwater released by underground movements, and it is also caused by some rain.

The usual drinking water for people is freshwater. The total amount of water on the earth is 1.4 billion cubic kilometers, there is a lot of water on the earth, and the reserves of fresh water only account for the total amount of water in the world, and some of them belong to solid glaciers, which are distributed in the high mountains and the north and south poles that are difficult to use, and some fresh water is buried deep underground, which is difficult to exploit. At present, human beings can directly use only groundwater, lake freshwater and riverbed water, the sum of the three accounts for about the total amount of water on the earth, human beings use more and more freshwater resources, except for the deep groundwater that can not be exploited, human beings can actually use only about the total amount of water on the earth.

To date, human freshwater consumption accounts for 54% of the world's available freshwater volumeHowever, the problem of freshwater pollution has not been completely eliminated. Therefore, the protection of water quality and the rational use of freshwater resources have become major issues of general concern to mankind today.

Seawater contains a large number of salts and a variety of elements, many of which are needed by the human body. However, the concentration of various substances in seawater is too high, far exceeding the drinking water health standard, if a large amount of drinking, it will lead to excessive entry of certain elements into the human body, affecting the normal physiological function of the human body, and serious poisoning.

If you drink seawater, you can take a lot of fresh water to remedy it. Large amounts of fresh water can dilute the excessive intake of minerals and elements by the body, excreting them from the body through sweat.

According to statistics, among those who died at sea, the mortality rate of those who drank seawater was 12 times higher than that of those who did not. Why is that? It turns out that the human body has to excrete about 150 grams of water in order to excrete 100 grams of salts contained in seawater.

Therefore, people who drink seawater not only cannot replenish the water that the human body needs, but also accelerate dehydration, and eventually cause death.

Seawater is drinkable after desalination. But it is more troublesome and costs a lot.

In special circumstances such as distress and life-saving at sea, in order to save fresh water, part of the seawater can be mixed with fresh water for drinking. Some people have done experiments that people drink a mixture of seawater and freshwater for a short period of time, which is generally harmless to the human body.