to become part of a group or team
加入一个团队或小组 (jiaru yige tuandui huo xiaozu)
"She’ll join up with the outreach crew tomorrow."
"她明天将加入外展团队。" (Ta mingtian jiang jiaru waichuan tuandui.)
to stop resisting or to agree after initial refusal
in the same situation or facing the same challenges
to help someone improve their situation or get an advantage
to help someone recover from illness
to be very close friends
advancing quickly in a career or project