Answer: D
Explanation: endocrine gland cells that secrete hormones (chemical messengers), which are carried in the bloodstream to the target cells which they act upon
Answer:
Periosteum, dense fibrous membrane covering the surfaces of bones, consisting of an outer fibrous layer and an inner cellular layer (cambium). The outer layer is composed mostly of collagen and contains nerve fibres that cause pain when the tissue is damaged.
I think its salinity because the other things have something to do with tracking precipitation