14. Mary is skating.
*Is Mary skating?* Yes, she is. / No, she isn't.
15. My parents are going to bed.
*Are my parents going to bed?* Yes, they are. / No, they aren't.
**Объяснение:**
Чтобы задать вопрос в Present Continuous, нужно поставить am/is/are перед подлежащим. Краткие ответы: Yes, подлежащее + am/is/are. / No, подлежащее + am/is/are + not.