i just learnt this recently but i need to look through my notes again.
The seasons. This is because when Earth is on an angle, different parts of the world get different amounts of heat, making temperatures different, and therefore changing the environment.
Answer:
Latent heat of fusion of the substance is 
Explanation:
Latent heat of fusion denotes amount of energy (heat) per unit mass required to melt a solid material at constant temperature and pressure i.e. at it's melting point
Here amount of heat required = 
Mass of unknown substance being melted = 18.5 kg
So, latent heat of fusion of the substance = (required heat energy to melt)/(mass of the unknown substance) = 
So, latent heat of fusion of the substance is 