A sentence has been given in Direct/Indirect Speech. Out of the four given alternatives, select the one which best expresses the same sentencein Indirect/Direct Speech
Conduction is the movement of heat through a substance by the collision of molecules. It occurs when two object at different temperatures are in contact with each other. Heat flows from the warmer to the cooler object until they are both at the same temperature.
A sentence has been given in Active/Passive Voice. Out of the four given alternatives, select the one which best expresses the same sentence in Passive/Active Voice.