The owl is also a bird of prey in ancient times. It has a wide range of uses and can be used in everything.
The first to catch mice. The plague of field mice has been a long time. Its cropping destroys the barn, which is a great harm to farmers. The owl is good at hunting mice. Its eyes are keen, and its night vision is like day. In the dark night, it can detect the traces of mice; its claws are sharp, like hooks and halberds. If hit with one hit, the rat cannot escape. Therefore, between the acres of fields, the owl is the guardian of the grain, protecting the harvest of the farmers, and it has no great contribution.
Furthermore, the owl also has a great contribution in maintaining the ecological balance. The ecology of nature is interlocked, and one thing is one thing. The owl feeds on rodents and insects, so that their populations do not flood, so as to maintain ecological harmony and stability. In the mountains, forests and fields, if there is no check and balance of owls, rats and insects will reproduce excessively, the grass and trees will be damaged, and the ecology will collapse.
In addition, in the ancient culture, the owl also has a special meaning. Although there may be viewers who regard it as ominous, there are also people who regard it as a symbol of bravery and protection. Its image is often seen on many ornaments and utensils, carrying the beliefs and prayers of the ancients. For example, in some rituals, the image of the owl may be used to repel evil spirits and protect peace.
To sum up, owls are important in trapping rats and protecting food, maintaining ecology, and carrying culture. They should not be underestimated due to their differences in appearance or habits.

The owl is also a bird. Its physical properties are quite special, and it is unique between heaven and earth.
First of all, its feathers. The owl's feathers are soft and dense. Its feathers are soft, and when flying, it can reduce the sound of the wind, so that it can travel in the air without making a sound. This is a wonderful tool for hunting. Just like a stealth guest in the night, he can approach his prey quietly without making him feel it. Its dense feathers have an excellent warm effect, even on a frosty night, it can withstand the cold outside world and keep the temperature in the body constant.
Second of all, on its eyes. The owl's eyes are large and round, and its eyes are very sharp. Its night vision ability is particularly outstanding. In the dark night, it can see objects as day. Gai has many rod cells on its retina, which are extremely sensitive to low light. And its eyes are forward, with a wide overlap in the field of vision and a strong three-dimensional sense. It can accurately judge the distance and orientation of the prey, so it can accurately capture the prey when the night is shrouded. Even if the pika is agile, it is difficult to escape its eyes.
In addition, the claws of the owl are sharp and powerful. Its claws are like hooks, and the grip is quite strong. Once it captures the prey, it is difficult for the prey to break free. When it falls from the air, where the claws fall, the prey is controlled by it. And the structure of the claws is flexible, and the grasping angle and strength can be adjusted in an instant to adapt to the shape and struggle of different prey.
It also has its beak, which is hard and curved. This beak is conducive to tearing the skin and flesh of the prey and pecking its bones. After capturing the prey, the owl handles the food with its beak, or swallows it whole, or bites it, relying on this hard and curved beak.
The body of the owl is different in size, but it is light and easy to fly. Its bones are hollow, and it can lose weight while maintaining its strength. It can soar freely in the sky and shuttle between forests and fields, showing its agility. Its physical properties are all suitable for its night hunting habits and survival needs. On the stage of nature, it interprets a unique survival chapter.

Mercury Dan is an ancient elixir, and its chemical properties cannot be hidden.
The main component of mercury Dan often contains mercury oxide and the like. According to its chemical composition, the stability of mercury oxide varies under certain conditions. At room temperature, mercury oxide is still relatively stable, but in case of extreme conditions such as hot topics, its properties will change. If heated to a certain extent, mercury oxide will decompose to form mercury and oxygen. This decomposition state shows that its chemical properties are not absolutely stable.
Furthermore, if mercury Dan encounters chemical reagents such as acids and bases, chemical reactions will also occur. When exposed to acid, new substances such as mercury salts may be produced. During this process, the original chemical structure and properties of mercury pills change, indicating that its stability is difficult to be constant under different chemical environments.
And mercury in mercury pills already has special chemical activity. Mercury is prone to valence changes, or is oxidized, or reduced in many chemical reactions. This property also causes unstable factors in the overall chemical properties of mercury pills.
The ancient people made mercury pills, which were mostly used for alchemy and cultivation. However, at that time there was limited understanding of its chemical properties. From a scientific perspective, the chemical properties of mercury pills are not completely stable, and they will show various chemical changes under different external conditions. Therefore, the chemical properties of mercury Dan cannot be simply regarded as stable and unchanged, and its chemical nature can be better understood by studying its environment and possible reactions.

The Tibetan Mastiff is a fierce dog. When it is stored, many matters need to be paid attention to.
First, the residence should be suitable. Tibetan Mastiffs like open and wide places, so the enclosure should be spacious and well-ventilated, allowing them to move freely. A dry lying place should be set up in the enclosure to avoid moisture and cold to prevent diseases.
Second, food and feeding should be careful. Tibetan Mastiffs have a large amount of food, and they should mainly eat meat, and also use grains, vegetables, etc., to ensure their nutritional balance. Feeding should be regularly and quantitatively, so as not to make them hungry and unstable, resulting in gastrointestinal damage. And drinking water should be clean and changed frequently to maintain their health.
Third, training must be strict. The Tibetan Mastiff is strong in nature. Strict training should be given since childhood to teach it to be meek and obedient, and to understand human instructions. During training, rewards and punishments are clear, so that they know what to do and what not to do.
Fourth, you must be diligent in epidemic prevention. Vaccinate it on time to prevent various diseases. You should also pay attention to its physical condition every day. If there is any abnormality, please contact the veterinarian for diagnosis and treatment as soon as possible, and do not delay the illness.
Fifth, get along well with each other. Although the Tibetan Mastiff is brave enough to protect its master, it should get along with others, and treat them kindly, often interact and play with them, and increase their friendship with others. In this way, the Tibetan Mastiff can be loyal and Tibetan mastiff owners should pay more attention to all these matters in order to make the Tibetan mastiff grow healthily and do their best to protect it.

Mercury is very toxic, and ordinary people are afraid to avoid it. However, in ancient alchemy, medicine and other fields, it has also explored its synthesis method. The following is a description of the synthesis of mercury in ancient times.
In ancient times, there was a recipe, based on Dan sand. For Dan sand, mercury sulfide is also. "Baopuzi Inner Chapter" states, "Dan sand burns into mercury, accumulates and becomes Dan sand". The method is to take Dan sand and put it in an airtight container and calcine it with fire. Dan sand is heated and decomposes into mercury and sulfur. Mercury is a liquid metal, which is volatile when heated and needs to be collected skillfully. The ancients often used the method of condensation to make the mercury vapor turn into a liquid when cooled and concentrate in other vessels.
Another method is to smelt lead and mercury. Lead is also commonly involved in ancient times. Lead is combined with mercury-containing ores or other mercury sources in a cauldron furnace. After a long period of high temperature refining, lead and mercury undergo complex chemical reactions. Lead is active, or interacts with mercury compounds to precipitate mercury. In this process, the control of the heat is extremely critical. If the fire is small, the reaction will be slow, and the mercury will be difficult to separate. If the fire is large, the mercury will easily escape and dissipate, causing it to fall short.
In addition, there have been attempts to smelt with mercury-related raw materials such as gallalum and saltpeter. For gallalum, copper sulfate crystals are also used; saltpeter, the main component is potassium nitrate. Mix all things in a certain proportion and heat them in a special appliance. In this process, various substances react with each other, or change the existing form of mercury, making it easier to extract or synthesize new substances with other substances. However, these methods are dangerous, and the success rate is not high due to impure raw materials and complex operations.
The ancient mercury synthesis method, although limited by the cognition and technology of the time, has many flaws, but the spirit of exploration of the ancients is particularly commendable. Its experience and attempts have also left valuable wealth for the development of chemistry in later generations.