why must the life cycle of sexually reproducing species alternate between haploid and diploid stages?

the plates spread at mid-ocean ridges (they are divergent plate boundaries) which allows magma to rise through the weakness between the plates. the magma then emerges as lava from the boundary and cools, creating a new crust.

there are men and women, some choose to be both or change their gender. often times those people go by "other". those who change their gender are known as "transgender"

out of the choices i'd say d the ability to set goals, mainly because to desire to continue you need motivation but it isn't motivation in that part, but setting goals means you have an endgame and you want to reach it which sums up motivation.