6. When my parents were young, they could play tennis very well. When What

Пояснение:

Задача состоит в том, чтобы сформулировать "специальные вопросы" (Wh-questions) к выделенным частям предложения. Вопросы должны начинаться с соответствующих вопросительных слов (When, What).

Пошаговое решение:

1. Предложение: "When my parents were young, they could play tennis very well."
2. Выделенная часть 1: "When my parents were young" (когда).
3. Вопрос к "When my parents were young": Начинается с When. Получаем: When could your parents play tennis very well?
4. Выделенная часть 2: "play tennis very well" (что делать).
5. Вопрос к "play tennis very well": Начинается с What. Получаем: What could your parents do when they were young?

Ответ: When could your parents play tennis very well? What could your parents do when they were young?