“backup” 的意思是：n. 备份；副手；助手；支持者；替补队员；v. 备份；支持；替补。
中英文例句：
I always backup my files before I leave the office. 我离开办公室之前总是先备份文件。
The police backup arrived soon after the alarm was raised. 报警之后不久警察增援就到达了。
He is a good backup player who can fill in when needed. 他是一名优秀的替补球员，在需要的时候可以顶替上场。
