Rain, clouds, sun, hail, which is different?

Among these four options, hail is a different category from the other three. The following is the explanation of this problem:

1. Rain: Rain is the phenomenon that water falls from the clouds to the ground, which is usually formed after gaseous water is cooled to a liquid state.

2. Clouds: Clouds are suspended water droplets formed by condensation of water vapor in the air, usually caused by changes in temperature or humidity.

3. Sun: The sun is a star and one of the important celestial bodies around the earth, which has an important influence on the earth's climate and ecosystem.

4. Hail: Hail is solid water, which usually rises to the sky by water droplets or ice crystals in the clouds. Due to the sudden drop in temperature, these water droplets or ice crystals quickly freeze into ice cubes and fall from the clouds.

Therefore, rain, clouds and the sun are all meteorological phenomena or astronomical phenomena, while hail is a solid precipitation phenomenon.