With the rapid development of science and technology, the raw materials of high-rise building doors and windows in foreign developed countries have gone through three stages of "wood iron aluminum alloy". More than a decade ago, they all began to enter the era of replacing aluminum alloys with hard plastics. In recent years, technicians have designed many plastic-steel parts on cars, trains, ships, and planes to replace wood, iron, aluminum and other parts, and their functions are far superior to the former.

Replacing wood with plastic, steel with plastic, copper with plastic, and aluminum with aluminum is not only the inevitable trend of scientific and technological progress, but also the only way for the development of China's manufacturing industry in the future. Tables and chairs are no exception. Moreover, the future table and chair can not only adjust the height, but also have a connecting table and chair, which is composed of a height-adjustable table and chair and a distance-adjustable connecting plate.

　　The desk and chair manufacturer has solved the problem that the existing desks and chairs for primary and middle school students cannot adjust the height, chair height, and distance between desks and chairs. It is suitable for students of all grades and body types in spring and autumn. Condition adjusted to fully meet the hygienic norms for tables and chairs.

　　After in-depth research, desk and chair manufacturers found that the reasons for the low fit rate of desks and chairs are as follows. The school bag can only be placed on the chair. The height of the desk and chair of different heights in the national standard is based on the correct sitting posture. The correct sitting position requires that the back two-thirds to three-quarters of the student's thighs should be placed on the surface of the chair, with the feet naturally flat on the ground, so that there is no significant pressure under the popliteal fossa.