短語詞組短語severely degraded GPS signal GPS 弱信號(hào)degraded service signal 降級服務(wù)信號(hào)Degraded signal defect 劣化信號(hào)缺陷Signal Degraded 信號(hào)劣化trail signal degraded 路逕信號(hào)劣化 返回 degraded signal