1. Born in a rich family, he is lazy and has never worked. When his family's wealth suddenly dropped he became a beggar. He is a failure and a loser in society.2. My mom let her family down and gave birth to a baby girl. In Chinese tradition a boy is more desirable than a girl.3. When the team was down by two points, Jason caught the ball and missed the three pointer. Jason failed the team.
 a failure a loser let somebody down fail somebodyfail somebody 就是讓某人失望的意思，跟 let somebody down 一樣。