Bilabials are sounds ( ) .
formed by bringing the tips of the tongue to the rear part of the alveolar ridge
produced by both lips
produced by the contact between the upper teeth and the lower lip
made with the tip of the tongue behind the upper front teeth or with the tongue tip between the upper and lower teeth.
本题考查双唇音。
双唇音是指用双唇来阻止或限制空气流动的辅音，例如[p] [b] [m] [w]。
