Many young people decided to join up during the war
She decided to join up with the local theatre group
If you want to learn a new skill, you should join up for a course
The two companies decided to join up to create a larger entity
He wants to join up the army as soon as he finishes school
Let's join up the ends of the rope to make a loop
Are you thinking of joining up with that new startup?
She encouraged her son to join up for the soccer team
The doctor explained how to join up the different pieces of the medical equipment
They plan to join up their businesses to expand their market reach
I heard they are looking for new volunteers.
Really? I might join up with you.
That would be great! We should go tomorrow.
The soldiers decided to join up for the cause
The soldiers enlisted for the cause
They volunteered to serve the cause