sonar/ˈsoʊ.nɑːr/名词声纳,声呐(一种声波探测仪器,用声波测定水的深度或水下物体的方位)The submarine used sonar to detect the presence of other vessels in the murky depths of the ocean.潜艇使用声纳来探测海洋深处的其他船只的存在。想跟读,去练习