t is difficult for us to learn a lesson in life ____we have

t is difficult for us to learn a lesson in life ____we have it is difficult for us to learn a lesson in life we have act it is difficult for us to learn a lesson in life until we've it is difficult for us to learn a lesson in life _____ we've It is difficult for us to learn a lesson in life until we ha It is difficult for us to learn a lesson in life()we've actu It is difficult for us to learn a learn in life ___we have a 英语翻译It's difficult for us to learn a lesson in life until we it is difficult for us to learn a lesson in life____we've ac It's difficult for us to learn a lesson in life____ we've ac It's very difficult for us to learn a lesson in life__we've ( ) It's difficult for us to learn a lesson in li