1. They would have traveled by car if they had thought about this opportunity beforehand.
2. Alexei would have stayed at his grandparents last year if he hadn't gone to the sports camp.
3. His friends would have chosen a present for him if he had told them about his birthday beforehand.
4. I should have read this book if you had given it to me last week.
5. My parents would have bought a voucher for me if I had told them about my plans.
6. They wouldn't have gone abroad on vacation if they had bought the furniture for the kitchen.
ответ:was built
Объяснение: