邻居们正在合作清理社区公园。

The neighbors are ___cooperating to clean up the community park.

两个团队正在密切合作完成这个项目。

The two teams are ___cooperating closely to finish the project.

团队成员们正在紧密合作，以确保项目按时完成。

The team members are ___cooperating closely to ensure the project is completed on time.