[] the service that hotels provide of telephoning guests to wake them up at the time they ask（酒店的）叫早服务◆Could I have a wake-up call at 6?可以在六点叫醒我吗？a sudden warning that you need to take action警示◆The shocking figures were a wake-up call to the sales team.这些令人震惊的数字提醒销售团队必须采取措施。