7. Last summer we (to go to see) the village where my father (to work) before he served in the army. 8. Then she (to remember) that she (to leave) the keys in the car. 9. John (to tell) me that he (to invite) his new friends to visit him in Tennessee. 10. He (to say) that his parents (to buy) him a computer last week.

7. Last summer we went to see the village where my father had worked before he served in the army.
   Прошлым летом мы поехали посмотреть деревню, где мой отец работал до того, как пошёл служить в армию.

8. Then she remembered that she had left the keys in the car.
   Затем она вспомнила, что оставила ключи в машине.

9. John told me that he had invited his new friends to visit him in Tennessee.
   Джон сказал мне, что пригласил своих новых друзей навестить его в Теннесси.

10. He said that his parents had bought him a computer last week.
    Он сказал, что его родители купили ему компьютер на прошлой неделе.

Объяснение: действия had worked, had left, had invited, had bought произошли раньше других действий в прошлом, поэтому употребляется Past Perfect. Действия went, served, remembered, told, said выражены формой Past Simple.