Affix is the collective term for the type of formative that call be used only when added to another morphemE.Affixes are limited in number in a language, and are generally classified into three subtypes, namely, prefix, suffix, and______.

A.

【参考答案】

Infix
词缀是那些只能附着于另一个语素(词根或词干)上的一类语素的总称。词缀都是粘着语素，可分为前缀、中缀和后缀三种。