The classification and description of English vowels are based on（ ）_________.
A.the position of the tongue B.the shape of the lips C.the shape of vocal tract D.all of the above正确答案D
The classification and description of English vowels are based on（ ）_________.
A.the position of the tongue B.the shape of the lips C.the shape of vocal tract D.all of the above正确答案D
