Bob Black usually wakes up about five minutes before the alarm clock goes off.
问题描述：
Bob Black usually wakes up about five minutes before the alarm clock goes off.
答
Bob Black一般在闹钟铃响之前五分钟左右就醒了。
go off这里指闹钟、爆竹等发出响声。
答
Bob Black 经常在闹钟响之前5分钟醒.
答
鲍勃 布莱克（Bob Black）通常在闹钟响起(go off原意为爆炸)前5分钟醒来