ecotourism pay for conservation efforts.
the element that provides strength to the exoskeletons of clams and oysters is phosphorus. this is so because calcium carbonate is the main component in the shells.
regulates body hormones, aldosterone, vasopressin
signal, regulates body using electric signals, reflex
endo has to do with hormones; aldosterone and vasopressin are both hormones. i also had this question and got it right : d