短語(yǔ)詞組短語(yǔ)fall -back state [計(jì)]低效運(yùn)行狀態(tài)Fall -Back Control 候補(bǔ)控制automatic fall -back 自動(dòng)下降Multiple fall -back mode 多級(jí)后備控制模式 返回 fall-back