12面体扬声器系统
dodecahedron loudspeakers system
高保真立体声微型耳机
high fidelity stereo micro earphone
集成微麦克风和微扬声器
Integrated Microphone and Microspeaker
正四面体结构模型
Tetrahedron structure model
共棱正四面体
co-edge regular tetrahedron
体心正四面体
body-centred regular tetrahedron
正四面体晶核
Crystal coren regular tetrahedron