Answer :
answer
1)the direction is from the body of a high temperature to a body at a low temperature
2)at the melting point and boiling point because the heat given is used to break down the forces holding the particles together so that they can change their state
3)In a gas because the particles of gases are held by weak forces thus have large intermolecular spaces between the particles while the solids are in a fixed position
4)heat is transferred to another body if they experience different temperatures