7) It seems only yesterday that your mother and father ___ in here buying their first wands. (be)

Решение:

Фраза "It seems only yesterday" указывает на то, что событие произошло в прошлом, но ощущается как недавнее. Поэтому используется Past Simple. Глагол "be" в Past Simple для "your mother and father" (они) будет "were".

7) It seems only yesterday that your mother and father were in here buying their first wands.