基本解释[经济学]外反馈式磁放大器词组短语短语external l feedback magnetic amplifier 外反馈式磁放大器external crack feedback magnetic amplifier 外反馈式磁放大器external feedback type magnetic amplifier 外反馈形磁放大器external feedback magnetic amplifier更多词组专业释义经济学外反馈式磁放大器