Answer:
4
Explanation:
Carbon has four valence electrons, so it can achieve a full outer energy level by forming four covalent bonds. When it bonds only with hydrogen, it forms compounds called hydrocarbons. Carbon can form single, double, or triple covalent bonds with other carbon atoms.
Oxygen would be the best answer
They can use those recently discovered genes and insert them in another species (fruits and vegetables) using genetic ingeniery technics so they can speed up the cell division on them, and accordingly increase the production.
Epithelial tissue mainly...but you can say statified epithelial tissue
