When metal conducts heat , that metal expands.
When a metal rod is warmed, the transfer of heat is by conduction.
When metal is warmed, the transfer of heat expands the metal.
When metal is warmed, the transfer of heat does what to metal?
Options:
  - expands
  - Energy.
  - breaks
  - blossoms
  - burning
  - voltage
  - improve
  - decreases