An eminent neurologist(神经学者), Eric Lenneberg, argued (Lenneberg, 1967) that the human capacity for language acquisition develops according to built-in biological schedules. Native language learning, he claimed, (1)_____________________________which lasts from about two until the onset of puberty(青春期), at about age thirteen. (2)___________________________________.Children aged two or three who suffer brain damage may lose all or part of the language they have learned, but are able to begin the learning process again, (3)____________________.
When children suffer aphasia(失语症)between four and ten and begin learning language again, recovery is usually complete, even if requiring several years.