暗中合作

例句：

1. 1. We must work together to solve this problem.
   我们必须共同努力解决这个问题。
2. 2.The team members need to collaborate effectively to achieve the project goals.
   团队成员需要有效地协作以实现项目目标。
3. 3. They decided to team up with a local company to expand their business.
   他们决定与一家当地公司合作以扩大他们的业务。