Education services, namely, providing tutoring and mentoring services, personalized courses of instruction, small group courses of instruction, diagnostic, remedial and prescriptive courses of instruction, standardized test preparation courses of instruction and study skills courses of instruction in the fields of general education and special education at the primary and secondary levels, namely, for students in pre-kindergarten, grades 1 through 12, and adults; education services in the nature of early childhood instruction provided at an early childhood education center; standardized testing; educational services, namely, providing classes and seminars in the field of professional development for teachers