Which type of plant only lives about a year?
annual
nonvascular
perennial
vascular

annual

Plant life cycles are annual, perrennial, biannual.

Alternation of generation is what happens in the asexual reproduction of vascular plants in their gametes, as haploid cells that came from their gametes, spores fertilizes another plant becomes a diploid cell in the process.

In terms of vascular plants, they help maintain the water cycle. The property of these plants enables them to carry out this function is their well-developed vascular system. 

They formed the oceans.  as they melted water was formed and the water made the oceans