I explain:

You know. I have a lot in life.
I saw. But recently,
moved to a new apartment.
The house is quite old, but
Absolutely strong. You know,
What killed me? Ventilation
In the pool! At the corner of each
rooms (except the bathroom and
Toilet on the floor.
The ventilation holes.
I have been trying for a month.
Solve the mystery – why? for
What is? What is their meaning?

Ventilation of wooden floor structures. In order for the tree not to rot it needs to be ventilated.