双向扬声器bidirectional: 双方向的; 双向的; 双向性的,8字型指向的; 双指向性loudspeaker: 广播喇叭; 嗽叭; 扬场器; 音箱backward and bidirectional: 反向与双向的bidirectional algorithm: 双向算法bidirectional amplification: 双向放大下载手机词典可随时随地查词查翻译