HELPPP PLEASE IT'S ABOUT CALCULATING ABUNDANCES i will give brailiest

An example of technology is the a. addition of a side group to an organic molecule during synthesis. b. use of a new antibiotic to fight an infection. c. measurement of iron concentration in a water sample. d. study of atomic fusion reactions

In which layer of earth do most earthauakes occur a_ inner core b_outer core c_mantle d_crust

The rules of engagement (roe) working group is often used to (select all that apply.)