backup是什么意思（backup）

1、backup.名词 n.1.帮助；援助；支持 military backup军事援助2.替代物;备用品;支援人员, 后备, 后补, 助手 a backup singer for Stevie Wonder史蒂维·旺德的伴唱歌手The hospital has a backup generator in case there is a power failure.医院有备用发电机以防停电。 2...