冲哥是个姐
Backup; spare; reserve; standby; alternate 请问是备用什么呢? e.g., Most hospitals have backup generators in case of blackouts. It's best to always carry a spare tyre when driving long distances. I had to dip into my reserve funds when the business got into trouble.
一谷鱼vegfish
备用 [简明汉英词典]standby:standby [简明英汉词典][5stAndbaI]n.可以信任的人, 使船待命的信息备用spare wheel:spare wheel [简明英汉词典]备胎,备用轮胎backup :[简明英汉词典][5bAkQp]n.后援, 支持, 阻塞vt.做备份adj.候补的, 支持性的[计] 文件备份