1, Winter Olympics city and temperature: positive and negative. Previous Winter Olympics are usually held in February, and the temperature-17℃ ~ 10℃ is the most ideal temperature.

2. Graphics in the Winter Olympics: axial symmetry and central symmetry. The medals of the Winter Olympics are round, the five rings of the Winter Olympics are axisymmetric figures composed of five circles, and the snowflake guide card is central symmetry.

3. Year of Winter Olympics: arithmetic progression. The Winter Olympics is held every four years. This year is the 24th Winter Olympics. 2 1 What year is the Winter Olympics?

4. National flags of different countries: shapes and proportions. The national flags of all countries in the venue are basically rectangular and look similar, but the ratio of length to width is not exactly the same. For example, the ratio of the national flag of China is 2:3, that of the American flag is 10: 19, and that of Sweden is 5:8.

5. Skiing track of platform: parabola. Take platform skiing as an example, the speed assisted by the skater can reach 24m/s, and we will see a beautiful parabola when the skater slides.