Look at the time circle and write the time square. The sun is round and the square is another name for the sun.
People and animals are unhealthy without it, and 90% of vitamin D needed by human body needs to be obtained by sunbathing.
Winter is short and summer is long. In winter, the sun appears for a short time during the day and sets at five or six in the afternoon. In summer, the sun appears for a long time during the day.
Without it, crops will not grow, and crops can grow and develop through photosynthesis only under the condition of light.
Extended data:
Sunbathing can prevent skin diseases. Proper exposure of the skin to ultraviolet rays can effectively kill bacteria on the skin and increase the skin's resistance.
Sunbathing can also enhance human immune function and increase the vitality of phagocytes. Ultraviolet rays in the sun have a strong bactericidal ability. Generally, bacteria and some viruses will be killed if they are exposed to the sun for half an hour or several hours.
Sunshine also has a certain regulating effect on people's life rhythm and psychology. Sunbathing can promote blood circulation, enhance metabolism and regulate the central nervous system, thus making people feel relaxed and comfortable.
Sunbathing can improve male androgen level, enhance sexual desire and improve sperm quality. Because the testosterone level in human blood will increase with the increase of vitamin D content in the body. The study also confirmed once again that the daily sunshine of 1 hour can increase testosterone in human body by 69%.