3. Wo machst du Gymnastik?

German to Russian Translation:

3. Where do you do gymnastics?

Answer (German):

• Ich mache Gymnastik in der Turnhalle.

Translation (Russian):

• Я занимаюсь гимнастикой в спортзале.

Explanation: 'in der Turnhalle' means 'in the gymnasium'. 'Turnhalle' is a feminine noun, and for a location (where), the dative case is used, hence 'in der'.