Answer: Mosses retain soil humidity and prevents its degradation, besides are habitat for little invertebrates.
Explanation: Mosses are non-vascular plants (they don't have conductive vessels as xylem and phloem) that live places as tree trunks, rocks, walls and soils. This habitats must be humids because mosses need water for nutrient transport, because they don't have cuticle (prevents water lost) and for fertilization. Mosses are important for the ecosistems where they live because retain water in the soils thus prevent erosion and harbor invertebrates as Tardigrades (water bears).
Because the stream comes from the watershed, anything being put into the watershed would eventually get into the stream, even if it's a contaminant.
its true all stars in a given star cluster from the same nebula
The risk of bleeding in the skull, which increases with age is most directly related to shrinkage of the brain. Brain shrinkage occurs as one grow older and is responsible for memory loss and reduced mental alertness. It has also been directly associated with premature death. Brain shrinkage is caused by aging together with its characteristic diseases such as diabetes, cardiovascular diseases, obesity, etc.