Complete the paragraph by choosing the correct answer.

Less. convection
more. sink
magma. current
density. temperature
heat. lithospheric.
mantle. rise
core. cycle
asthenosphere

1._______is a kind of 2._______transfer caused by differences in 3.______and 4._______of a gas, fluid or molten rocks. Hot fluid materials 5._______because they are 6._______dense, while cold fluid materials 7._______because they are 8._________dense. In the mantle, the repeating rising and sinking of 9._______creates a convection 10._______driving the 11._______plates that ride on 12.________to move slowly and constantly.​