Hahaha. For those wanting speaking exercises in the Polish course, here you go.
Is ćwiczenie used as a noun or verb here? If it's a noun, then "practice speaking" shouldn't be marked wrong, as practice can be either a noun or a verb
ćwiczenie is a noun (or, strictly speaking, it's a gerund - rzeczownik odczasownikowy). Practice speaking translates to Ćwicz mówienie.