联合

例句：

1. 1.The two countries have joined forces to tackle the issue.
   这两个国家已经联合起来解决这个问题。
2. 2. The scientists combined their knowledge to solve the problem.
   科学家们将他们的知识结合起来解决了这个问题。
3. 3. The team has united to achieve a common goal.
   团队已经团结起来为了共同的目标努力。