purevowel,purecolor

厂家直销 德国vowel重低音音箱 低音炮效果 sd卡 u盘商品大图
3 vowel glides pure vowels (or monophthongs ): vowel glides
vowels pure vowels单元音 diphthongs 双元音
into two large categories: monophthongs or pure/single vowels
vowels characteristics of "pure" vowels and diphthongs.