Ответ:
1. ... invited ... decided
2. Did ... have ...? - Yes, they had
3. Was ... were?
4. ... did ... cost?
5. ... did ... phone...?
6. ... saw ... .
7. Did it rain ...? No, it didn't
Объяснение:
Past Simple:
вторая форма глагола или глагол с окончанием "еd" в утвердительных предложениях
Did + глагол в первой форме в вопросах
Didn't + первая форма глагола в отрицаниях.