【正确答案】:
MORPHEMES WHICH CANNOT OCCUR AS SEPARATE WORDS ARE BOUND. BOUND MORPHEMES INCLUDE BOUND ROOT AND AFFIX. BOUND ROOT IS ONLY A TYPE OF BOUND MORPHEME.
【题目解析】:Morphemes which cannot occur as separate words are bound. Bound morphemes include bound root and affix. Bound root is only a type of bound morpheme.