首字母填空.Any attempt to study the decelopment from the noises b

首字母填空.
Any attempt to study the decelopment from the noises babies make to their first spoken words leads to considerable difficulties.It is agreed that they enjoy m____ noises,and that during the first few months one or two noises sort themselves as particularly expressive as delight ,pain,friendliness,and so on.But since these can't be said to show the baby's intention to communicate ,they can hardly be regarded as early forms of l____ .It is agreed,too,that from about three months they play with sounds for enjoyment,and that by six months they are able to add new words t____ their store.