In general, the most materially advanced and developed countries are focused on extensive development of the sector of their economy.
a. quaternary
b. secondary
c. tertiary
d. primary

answer: 45

explanationyou have to add as well to be it could be

69 is the correct math for the amino acids

the atomic number of magnesium is 12. its nucleus must contain 12 protons and no electrons. the atomic number of an atom is determined by the number of protons.

magnesium is an electrolyte injection commonly used to treat low magnesium levels in your blood. it is also used to prevent or control seizures in women with preeclampsia or eclampsia.