Which resource type is commonly bought by the Los Angeles Unified School District?
resource type refer to project_resource_type; most commonly bought refer to COUNT(project_resource_type where school_district = ’Los Angeles Unif Sch Dist’); Los Angeles Unified School District refer to school_district = ’Los Angeles Unif Sch Dist’
SELECT T1.project_resource_type FROM resources AS T1 INNER JOIN projects AS T2 ON T1.projectid = T2.projectid WHERE T2.school_district = 'Los Angeles Unif Sch Dist' GROUP BY T2.school_district ORDER BY COUNT(T1.project_resource_type) DESC LIMIT 1