Douglas fir tree is one of the most popular tree species in North America. It is a classic Christmas tree in Europe and the highest selling pine species. Because of its beautiful tree shape and fast growth speed, it can provide new ornamental trees for Christmas, scenic spots and landscaping.

Douglas fir tree has natural color, maintains the natural color of pine, and has clear and beautiful texture; Simple and generous shape, full and smooth lines, showing a good texture. Douglas fir tree is a kind of coniferous forest. Due to the high forest coverage, almost all trees have not been trimmed manually, which maintains the natural color of pine and has clear and beautiful texture, so that after being processed into wood, the branches leave traces of natural growth.

Source: @_dctattoos

The meaning of trash can tattoo is psychological pleasure. Crowded places need a clean and tidy park environment, and a reasonable waste treatment system is particularly important. In the environment of domestic waste treatment and leisure life, psychological pleasure is the original intention of the construction of these places, while in places such as urban streets, it is more necessary to have the ability to dispose of waste at will. The single pollution source of these wastes is not high, but the city has a large population and strong centralized pollution capacity. After dealing with these, the whole city will be very clean.

A clean and tidy city can improve the sense of mission of the city and maintain the sense of mission of urban cleanliness, and has a good effect on carrying out national quality education on campus. The trash can is produced according to the quality standard. It has a series of perfect production lines such as film cutting, stamping, welding, spraying and injection molding, plus perfect quality inspection means. This is the meaning of the trash can.

Source: @adamharmontattoo

Sunflower seed, the fruit of sunflower, can be used for food and oil. Sunflower seed is rich in unsaturated fatty acids, vitamins and trace elements. It tastes delicious. It is a very popular source of leisure snacks and edible oil.

Sunflower seeds are widely used and can be added to a variety of dishes. Because they are rich in protein, adding sunflower seeds to dishes can improve the nutritional value of food and add a unique crisp taste to salads, sauces, dishes, cakes and yogurt.

Source: @babie_lato_tattoo

Seesaw, a children’s toy with more than two people. Sitting on the seesaw, one person sits at one end, one person goes up and one person comes down. The seesaw principle is the lever principle, the pressure of people on the seesaw is power and resistance, and the distance from people to the fixed point of the seesaw is power arm and resistance arm respectively. The downward acceleration leads to one up and one down. The downward acceleration of the high is greater than that of the low, so the high drops. At the same time, the low is tilted up under the action of the lever principle, so it circulates.

If other children are playing on the seesaw, keep a distance while waiting. Never put your foot under the tilted seesaw, stand in the middle of the beam of the seesaw, or try to climb onto the seesaw that is tilting up and down.

Source: @beccasportfolio

The earliest traffic lights appeared in London, England in 1868. At that time, the traffic lights were only red and green. After improvement, a yellow light was added. The red light means stop, the yellow light means preparation, and the green light means passage. In fact, using these three colors as traffic signals is related to people’s visual function structure and psychological response.

With the development of various means of transportation and the needs of traffic command, the first true three-color light (red, yellow and green signs) was born in 1918. It is a three-color circular four-way projector, which is installed on a high tower on Fifth Street in New York City. Due to its birth, the urban traffic has been greatly improved.

Source: @dannyfgt