Simplify the following text for a Grade 10 native English-speaking person.
Original: It was announced on 21 June 2010 that Suzuka Circuit would host the Japan round of the 2011 World Touring Car Championship season instead of the Okayama International Circuit .
Simplified: It was announced on June 21 , 2010 that Suzuka Circuit would host the Japan round of the 2011 WTCC season instead of the Okayama International Circuit .