Complex sentence: He completed his first 8 classes at School no.11 Mihai Eminescu and secondary education at Ion Brătianu High School in Piteşti, and his undergrad and Ph.D. at Harvard University under the direction of Peter B. Kronheimer.
Split into simpler sentences: He completed his first 8 classes at School no.11 Mihai Eminescu and his secondary education at Ion Brătianu High School in Piteşti. He did his undergrad and Ph.D. at Harvard University under the direction of Peter B. Kronheimer.