常见 Back 短语及例句
back up – 备份；支持
例：Please back up your files regularly to avoid data loss.
back down – 让步；退缩
例：He refused to back down during the negotiation.
back away – 后退；退出
例：She slowly backed away from the angry dog.
back out – 退出（协议、承诺）
例：They decided to back out of the deal at the last minute.
back off – 撤退；停止施压
例：The police told the crowd to back off.