el problema es que angela era alérgica a su medicamento, por lo que su médico le dio un nuevo medicamento que la mejoró porque no era alérgica a él
El: if the next word ends in an o/or
La: a
Los: os/ors
Las: as
For example, number 5 would be "El radio pequeño esta en la cocina."
For the bottom:
If it's la/las it's feminine.
If it's el/los it's masculine.
Hope that helped. :)
"My brother plays tennis" hope i helped