Simplify the following text for a Grade 6 native English-speaking person.
Original: During World War I , IaÅ i was the capital of a severely reduced Romania for two years , following the Central Powers ' occupation of Bucharest on 6 December 1916 .
Simplified: When World War I happened , IaÅ i became the capital of Romania . This happened when the Central Powers took Bucharest on 6 December 1916 .