社区中心的聚餐是每人带一道菜的百乐餐形式。

The community center is hosting a ___potluck where everyone brings a dish to share.

参加这次创业比赛有点像碰运气，不知道哪个项目会胜出。

Joining this startup competition is a bit of a ___potluck — there's no telling which project will win.