The morpheme of the past tense marker /-ed/ is pronounced as /t/ in worked, /d/ in lived and /d/ in landed. This example shows（）.
问题1选项
A.morphemes are abstract units
B.morphs are actual spoken minimal carriers of meaning
C.allomorphs are phonetically conditioned and thus predictable
D.monomorphemic words coincide with words and function freely in a sentence
