twosome

例句：

1. 1.They were a twosome of friends who always supported each other.
   他们是一对朋友，总是互相支持。
2. 2.The twosome was the only team that could beat the other in the competition.
   这对二人组是比赛中唯一能战胜对方的队伍。
3. 3. She decided to be a twosome and help her sister with her studies.
   她决定成为一对二人组，帮助妹妹学习。