Complex sentence: Seo shortly had the opportunity at several full-lengths when in her second year as principal, three of ABT's senior principal ballerinas announced their retirement suddenly putting Seo at the front of the line for many of the lead roles.
Split into simpler sentences: Seo shortly had the opportunity at several full-length in her second year as principal. Three of ABT's senior principal ballerinas announced their retirement suddenly putting Seo at the front of the line for many of the lead roles.