世界性的饥饿问题是个极其难以解决的问题，我恐怕人们在我这一辈子都找不出解决的办法。 The question of world hunger is a very hard nut to crack. I doubt if we'll find the answer to it in my lifetime.
他小小年纪就已经做到一个普通人一辈子都完成不了的事情。 At such a young age, he's accomplished more than an average person can not do in a lifetime.
你能甘心一辈子失业吗？ Could you reconcile yourself to a lifetime of unemployment?
