Complex sentence: Ritzen started in 1963 on Bernardinus College in Heerlen, in 1970 he obtained an engineeringdegree in physics from the Technische Hogeschool Delft, now Technische Universiteit Delft.
Split into simpler sentences: Ritzen started in 1963 on Bernardinus College in Heerlen. In 1970 he obtained an engineering degree in physics from the Technische Hogeschool Delft, now Technische Universiteit Delft.