Which elements are common to all organisms? Which ones apply?? A. sodium
B. oxygen
C. Sulfur
D. Hydrogen
E. iron
F. phosphorus

B D

Explanation:

hope this is right but not entirely sure

explanation:

since this is put under health, i would define "ethical (medical) behavior" the way the oath for doctors is recited.   "first do no harm."

but the term in general means when given a choice between right and wrong, we should always choose right. if we do, then we are practicing ethical behavior.

the mantle

explanation:

earth is divided into three layers: the crust or the outermost layer on which we live; the underlying, middle layer - the mantle - and the core (the innermost layer of earth).