an arduous journey across the Andes翻越安第斯山脉的艰苦之行Take your ease, for the journey ahead will be long and arduous.好好休息一下, 前面的路程远而艰难呢.We must have patience in doing arduous work.我们做艰苦的工作要有耐性....
我当时不知道罗恩有那么坚强的个性。I didn't know Ron had that much strength of character.我不知道自己要去上哪所大学.I didn't know what college I wanted to go to.现在还不知道有多少人在枪林弹雨中身亡。It's still not known how many died in the volleys of gun...