血的教训 meaning in English

lesson paid for [written in] blood

We must bear in mind these lessons paid for with blood .
我们要记住这些血的教训。
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。
Life ' s like a box of chocolate . you never know what you ' re gonna get
现在有些吵着要看每一个帖子的新同学应该知道为什么有些帖子你没有权利看了吧？这都是血的教训！
四 the lessons drawn from the movement of elimination of counterrevolutionaries in the soviet areas are very bitter valuable . they were acquired at the price of the people " s blood in the soviet areas and we should n ' t and ca n ' t forget these blooding lessons
四湘鄂赣苏区肃反扩大化的教训是沉痛而宝贵的，它是用苏区人民的鲜血换来的，我们不应该也绝不能够忘记这血的教训。
Britons became painfully aware of the threat of home grown terrorism in july 2005 when 4 young local islamic radicals blew themselves up in london ' s subway system and on a bus , killing 52 commuters and injuring hundreds more
在2005年六月当4个年轻的当地伊斯兰激进分子在伦敦地铁站的一辆公汽上自杀式爆炸，造成52人死亡，一百多人受伤，英国政府在血的教训中意识到了国内恐怖主义威胁正呈上升趋势。