I don't know if you like to play tennis? When I was in school, I specially learned some basic common sense of tennis in physical education class, but they were all theoretically strong. Let me share with you some basic common sense about the sport of volleyball. (Competition clothing) 1. Sign belt and sign pole 1． The sign pole is 1.80 meters long and 10 mm in diameter. It is two flexible poles made of fiberglass or similar materials. Two marker bars are respectively arranged on different sides of the net along the outer edge of the marker band. The pole is 80 cm above the net, and every 10 cm above the pole is painted with a contrasting color, preferably red and white. The marker pole is part of the net and is considered the boundary of the net area. 2. The logo has a width of 5 cm, a length of 1 meter, and the color is white. The logo strips are placed on both ends of the net, perpendicular to the touchline. The two flags are considered to be part of the web and act as a boundary on the web. 2. In the official competition, the height of the adult men's net is 2.43 meters, the height of the women's net is 2.24 meters, and the height of the juvenile men's net is 2.24 meters.—2.35 meters, women's net height is 2—2.15 meters. The measurement of the height of the net shall be based on the height of the middle of the net, and the height of both ends of the net shall not exceed the specified net height by 2 cm. Third, the net column 1. The two net posts are installed at 0.50 from the sideline—1 meter extension of the midline. Formal large-scale games require an extension of the midline beyond 1 meter from the sideline. 2. The columns are two smooth cylinders with a height of 2.55 meters, which can be adjusted in height. There are generally two types of cylinders: zipper type or hole type. Formal competitions require the use of hole-inserted net posts to avoid injury. 3. There should be a sponge soft sheath outside the net column or wrap the net column with a similar soft cloth to prevent the athlete from being injured. Fourth, volleyball 1. The color of the volleyball can be monochromatic light or multi-colored. 2. A volleyball is a round, soft leather or artificial leather shell with a rubber or similar bladder inside. 3. Air pressure, circumference, weight of volleyball: the air pressure of the ball is 0.30—0.325 kg/cm², the circumference of the ball is 65—67 cm, the weight of the ball is 260—280 grams. The above is some basic knowledge about volleyball, which is very useful for Xiaobai to know tennis. For those friends who know tennis very well, you should review your homework.