natural selection

evolutionary theory that animals survive or become extinct according to their ability to adapt themselves to their environment 自然选择; 天择.

nationality, nationalization, nationalisation, nationalize, nationalise, nationally, nationwide, native, native speaker, native-speaking, nativity, nativity play, NATO (also Nato), natter, nattily, natty, natural, natural childbirth, natural gas, natural history, natural law, natural philosophy, naturalgas, naturalism, naturalist, naturalistic, naturalization, naturalisation, naturalize, naturalise, naturally, naturalness, nature, nature study, nature trail, naturism, naturist, naturopath, naturopathic, naturopathically, naturopathy, naught, naughtily, naughtiness,