Answer:
Convection
Step-by-step explanation:
heat: Can be defined as a form of energy flow due to temperature difference. The unit of heat is is Joules.
Method of heat transfer: There are three method of heat transfer and they are, conduction, convection and radiation.
Conduction : This is a process by which heat is transferred along a metal object.
Convection : This is a process by which heat energy is transferred in a fluid ( liquid or gas).
Radiation : This is the process by which heat is transfer from one source to another without heating the intervening medium.
Therefore Liquids and gases transfer heat by convection.