1. The arrangement of water molecules in liquid water is irregular. After solidification, the arrangement becomes regular. Due to the hydrogen bond, tetrahedral structure is formed between water molecules, which makes the gap between water molecules larger, so the volume of water becomes larger after freezing.

2. Curling track is not completely flat. Before the competition, the staff will spray every drop of water evenly on the ice, usually 2-3 mm, and the water drops will condense to form ice particles and pits. The purpose of this is to reduce the contact area between the bottom of curling and the ice surface, reduce friction and speed up curling.

3. Carbon dioxide is gaseous at normal temperature and pressure. After a certain pressure is applied, it can be liquefied into liquid or even condensed into solid (dry ice). After the pressure is reduced, liquid or solid carbon dioxide can be quickly vaporized (or sublimated) into gas, absorbing a lot of heat, thus achieving the purpose of reducing the environmental temperature.

4. The three sets of etiquette costumes "Xue Rui Xiang Yun", "Hong Yun Shan Shui" and "Tang Hua Xue Fei" in this Winter Olympics are elegant and generous in appearance, and graphene heating materials (mobile power supply is required) are specially added in the clothes liner, so that the staff will not feel cold even if they continue to work in a low temperature environment.

In the short track speed skating competition, all the players wear sharp skates. After the game, the skates will carve irregular thin lines on the ice. At this time, the machine will melt the ice by sprinkling water and heating, and fill the uneven ice with water. After freezing at low temperature, the ice will return to a complete and smooth state, which will not affect the next game.