A.1938 B.1955 C.1964 D.1972 E.1982
A.炭精助聽(tīng)器; B.半導(dǎo)體眼鏡式助聽(tīng)器; C.耳后式助聽(tīng)器; D.集成電路助聽(tīng)器; E.駐極體傳聲器助聽(tīng)器。
A.聲帶短、緊、質(zhì)量小; B.聲帶短、松、質(zhì)量??; C.聲帶長(zhǎng)、緊、質(zhì)量大; D.聲帶長(zhǎng)、松、質(zhì)量大; E.聲帶短、松、質(zhì)量大。