下列关于公路隧道坡度的说法正确的有（）

单项选择题The study of sounds is divided into three main areas, each dealing with one part of the process. ______ is concerned with the perception of speech sounds. A、Articulatory phonetics B、Auditory phonetics C、Phonological process D、Acoustic phonetics

多项选择题公路隧道与铁路隧道的区别有（）