"ocean" was marked wrong for moře...couldn't it also be correct?
sea = moře
ocean = oceán
How is the ř pronounced? I got a different z-like pronunciation in previous lessons using the name Kateřina but here they are using a T sound
Check https://forum.duolingo.com/comment/33220958/How-do-you-pronounce-%C5%99-in-Czech https://forum.duolingo.com/comment/28854629/Tongue-position-when-saying-%C5%98 and search the forum for more.
Dont hear more, always hear "mure" :-(
Both current voices are OK