视频对白：
Yeah, at the cost of my son.
是啊，可我失去了儿子。

今天要学习的词组为：at the cost of

意为“以…为代价”。

例句：
1. The lessons learned at the cost of blood helped to sober us.
血的教训使我们的头脑清醒了。

2. He rescued the boy from drowning at the cost of his own life.
他救这小孩免于淹死却牺牲了自己的生命。

3. The poor fox escaped from the trap at the cost of a leg.
那只可怜的小狐狸逃出了陷阱，却失去了一条腿。