【正确答案】正确答案：Assimilation is a process by which one sound takes on some or all the characteristics of a neighbouring sound. It is often used synonymously with coarticulation. Nasalization, dentalization and velarization are all instances of assimilation. There are two possibilities of assimilation: if a following sound is influencing a preceding sound, it is regressive assimilation; the converse process, in which a preceding sound is influencing a following sound, is known as progressive assimilation.