Explanation:
Heat transfer by convection involves gases and liquids as a result of density differences when they are heated.
In the hot air balloon, the air closer to the heater is warmed. This air becomes lighter and it rises. This in turn pushes the balloon up. The cold air away from the heater is denser and begins to sink.
This exchange of hot and cold air sets up convection cells within the balloon and this how heat transfer is attained.
They have different bodily functions
Explanation:
Someone of different origin may have a different lifestyle which may affect there life expectancy
when two air masses coming together the boundary between the two is called a weather front

Actually Welcome to the Concept of the History.
Environmental Problems, such as Pollution in the river are :
=> The main causes of water pollution in the Ganga river are the disposal of human sewage and animal waste, increasing population density, and disposal of industrial waste into the river.
=> Some of the dams being constructed along the Ganges basin will submerge substantial areas of nearby forest.
Social problems:
1. The Ganga Action plan (GAP) largely ignored public participation despite having funds allocated for it. It is interesting to note, therefore, that the NGRBP has made provisions for public participation although it has not yet outlined how it is to be implemented .
2.Lack of proper discharge of religious offerings.
3.Lack of creation of eco-friendly offerings made to the river.