backup
英 [ˈbækʌp] 美 [ˈbækʌp]
n.
(文件等的)备份;后援;增援
adj.
后补的;支持性的;伴奏的
例句
You should make a copy of the disk as a backup.
你应该将磁盘复制一个备份。
Always make a backup disk as an insurance policy.
为保险起见，每次都要做备份磁盘。
Maybe your first computer had a tape backup system.
也许你的第一台电脑还有支持磁带的系统呢。
