This is the 3782nd most frequent Spanish word.
registran
"Registran" means "they register" or "they record."
In this sentence, 'registran' is used as a reflexive verb indicating the action of the students registering themselves in the system.
Los estudiantes se registran en el sistema para acceder a las clases.
The students register in the system to access the classes.
In this sentence, 'registran' is used to indicate the action of the devices recording data, serving as a transitive verb.
Los dispositivos registran datos automáticamente.
The devices record data automatically.
Here, 'registran' is used impersonally to imply that the recording of low pollution levels is taking place within the context mentioned.