complement-on-two

例句：

1. 1.We need two more people to finish the project on time.
   我们需要再增加两个人才能按时完成这个项目。
2. 2. The teacher complemented my work with some additional explanations.
   老师对我的工作进行了一些额外的解释。
3. 3. The book is a great complement to your study of history.
   这本书是您学习历史的很好的补充。