The structure labeled X most likely helps with which activity? swimming climbing jumping fertilizing

sex cells are usually half's then they find another half and make a fertilize egg

igneous rocks are formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.  

the composition depends on the source magma. there are almost a thousand types of composition found till now.  

hope this

there's no big difference.

explanation:

the only little different between a rabbit and bunny is just that bunnies are much smaller than rabbits. bunnies are basically baby rabbits.

answer increasing the intensity, duration,and frequency of exercise progressively;