The main source of downward convection flow in the mantle is called
ridge-pull
slab-pull
slab-push
ridge-push

The right option is; slab-pull

The main source of downward convection flow in the mantle is called slab pull.

Slab-pull is the force applied by a cold, dense oceanic plate descending into the mantle as a result of its own weight. This process is known as subduction. The oceanic plate has a density higher than that of the hotter mantle below it and the difference in their density causes the plate to submerge into the mantle.

answer; ///i believe its: ///(embolus);

a

explanation:

many plants naturally reproduce this way, but it can also be induced artificially. horticulturalists have developed asexual propagation techniques that use vegetative plant parts to replicate plants. success rates and difficulty of propagation vary greatly. monocotyledons typically lack a vascular cambium and therefore are harder to propagate.