5. When I looked trough the window, the sun (to shine) but the wind (to blow).

Решение:

Используем Past Continuous для одновременных длительных действий (sun shining, wind blowing), происходивших в прошлом.

Формула: ... Past Continuous ... , ... Past Continuous.

• When I looked trough the window, the sun was shining but the wind was blowing.

Ответ: was shining; was blowing