This is the 5121st most frequent Polish word.
przejdą
"Przejdą" means "they will pass" or "they will go through."
The word 'przejdą' is used here as third person plural future tense of 'przejść', implying a movement across an obstacle, in this case, a bridge.
Wkrótce przejdą przez most.
Soon, they will pass over the bridge.
Here, 'przejdą' metaphorically refers to successfully passing or overcoming a challenge, specifically the exam.
Jeśli się postarają, przejdą ten trudny egzamin.
If they make an effort, they will pass this difficult exam.
In this sentence, 'przejdą' is used to mean 'disappear' or 'resolve over time', referring to abstractions such as problems disappearing.