sentences: a metal spoon is put into a very hot water & a hot substance is a source of heat ->  the metal spoon is exposed to a source of heat  a spoon sometimes is made of metal & metal is a thermal conductor ->  a metal spoon is a thermal conductor  a metal spoon is a thermal conductor & if a thermal conductor is exposed to a source of heat then that conductor may become hot ->  if a metal spoon is exposed to a source of heat, then the metal spoon will become hot  the metal spoon is exposed to a source of heat & if a metal spoon is exposed to a source of heat, then the metal spoon will become hot -> the metal spoon will get hot