PREEXISTENT
\pɹˈiːksɪstənt], \pɹˈiːksɪstənt], \p_ɹ_ˈiː_k_s_ɪ_s_t_ə_n_t]\
Word of the day
Quinones
- Hydrocarbon rings which contain two moieties position. They can be substituted in any position except at the ketone groups.