Question: List the first name of all the professionals along with the description of the treatment they have done.
SQL: SELECT DISTINCT T1.first_name ,  T3.treatment_type_description FROM professionals AS T1 JOIN Treatments AS T2 ON T1.professional_id  =  T2.professional_id JOIN Treatment_types AS T3 ON T2.treatment_type_code  =  T3.treatment_type_code