dct 基本解释 离散余弦变换 同首字母单词 d [diː] da [,di:'eɪ] daa dab [dæb] dabber ['dæbə] dabble ['dæb(ə)l] dabbler ['dæblə] dabchick ['dæbtʃɪk] dabster ['dæbstə] dac dacca dace [deɪs]