check out短语怎么理解？

For busy people, the idea of speed dating has really caught on in popularity. In a speed dating event, usually 8-10 singles go around from table to table, each spending 6-8 minutes at each one. From that, you may not know for sure if you want to develop something more with an individual, but, you willdefinitely know 
if you don't want to. 
The first thing that you will realize about 
speed dating is that it makes you focus . Unlike a bar, where you might get a whole evening 
to occasionally check a potential partner out and to see what they've got, when it comes 
to speed dating, you know that you only have a certain amount of time to put your best foot forward（全力以赴）there. You'll find the other participants are aware of this and will put their best foot forward. 
本文第二段第二句
Unlike a bar, where you might get a whole evening to occasionally check a potential partner out and to see what they've got，这句check out短语怎么理解？they指代的是谁？

全部

k***

回答