join forces
US /dʒɔɪn ˈfɔːrsɪz/
UK /dʒɔɪn ˈfɔːrsɪz/

1.
聯手, 合作
to combine efforts or resources with another person or group to achieve a common goal
:
•
The two companies decided to join forces to develop a new product.
兩家公司決定聯手開發新產品。
•
We need to join forces if we want to win this competition.
如果我們想贏得這場比賽,我們需要聯手。