Past Simple or Past Continuous, as in the example. He had had (have) the same computer for 5 years before he decided (decide) to change it.
1. Andy
(not/be) able to open the front door because it
(snow)
heavily all night.
2. While our children
(sleep) in the car, we
(cross) the
border with Estonia.
3. When we
(arrive) at the airport, we
(remember) that we
(leave) our passports in the car.
4. Polly
(look) frightened. She
(tell) us that she
(see) a big rat in the basement.
5. When a famous actress
(get) out of the car, everyone
(wave)
at her.
6. We
7. They
(not/move) until we
(redecorate) our new flat.
(walk) along the beach for two hours before they
(get) dark and then they
(decide) to
(notice) that it
go back.
8. He
(feel) thrilled. He
(travel) through the jungle.
(work) for that company for thirty years before he
9. Michael
(resign).
10. After Sue
(try) on a lot of shoes, she
(decide) to buy
dark blue ones.​

Ответ на ваш вопрос о временах Past Simple и Past Continuous в английском языке:

1. Andy wasn't able (not/be) to open the front door because it had been snowing (snow) heavily all night.

   Здесь используется Past Simple (wasn't able) для обозначения конкретного действия в прошлом, и Past Perfect Continuous (had been snowing) для действия, которое началось до момента в прошлом и продолжалось в тот момент.

2. While our children were sleeping (sleep) in the car, we crossed (cross) the border with Estonia.

   Past Continuous (were sleeping) используется для описания действия, происходившего в определенный момент времени в прошлом, а Past Simple (crossed) - для обозначения завершенного действия.

3. When we arrived (arrive) at the airport, we remembered (remember) that we had left (leave) our passports in the car.

   Здесь используются два времени: Past Simple (arrived, remembered) для последовательных действий и Past Perfect (had left) для действия, произошедшего до другого действия в прошлом.

4. Polly looked (look) frightened. She told (tell) us that she had seen (see) a big rat in the basement.

   Все глаголы здесь в Past Simple (looked, told), так как описываются последовательные действия, и Past Perfect (had seen) для действия, которое произошло до другого действия в прошлом.

5. When a famous actress got (get) out of the car, everyone was waving (wave) at her.

   Используется Past Simple (got) для одного действия и Past Continuous (was waving) для другого, происходившего одновременно.

6. We didn't move (not/move) until we had redecorated (redecorate) our new flat.

   Past Simple (didn't move) для действия, которое завершилось, и Past Perfect (had redecorated) для действия, завершившегося до другого действия.

7. They had been walking (walk) along the beach for two hours before it got (get) dark and then they noticed (notice) and decided (decide) to go back.

   Используется Past Perfect Continuous (had been walking) для длительного действия до определенного момента в прошлом, Past Simple (got, noticed, decided) для последовательных действий.

8. He felt (feel) thrilled. He had been working (work) for that company for thirty years before he resigned (resign).

   Past Simple (felt, resigned) для отдельных действий и Past Perfect Continuous (had been working) для действия, продолжавшегося до другого действия в прошлом.

9. Michael had worked (work) for that company for thirty years before he resigned (resign).

   Здесь используется Past Perfect (had worked) для действия, продолжавшегося в течение периода времени до другого события, и Past Simple (resigned) для этого другого действия.

10. After Sue had tried (try) on a lot of shoes, she decided (decide) to buy dark blue ones.

Past Perfect (had tried) для действия, произошедшего до другого действия, и Past Simple (decided) для второго действия.