Ответ:

1. After Jim and Ben had bought the tickets, they entered the theme park. (buy, enter)

2. After the boys had three rides, they felt hungry. (have, feel)

3. Mum had made and packed some sandwiches for them. So they just bought some drinks. (make, pack, buy)

4. The boys had took a ride on a roller coaster after they ate their sandwiches. (take, eat)

5. After coming off the roller coaster, Jim noticed that he had lost his cap. (notice, lose)

6. He asked a girl from the staff about his hat. The girl said that she picked on it up and passed the cap to the ticket desk. (ask, pick, pass)

7. After Jim had fetched his hat, they went to take a ride on the drop tower. (fetch, go)

8 When the boys had reached home, their parents asked if they had a good day. (reach, have)

Объяснение:

Past Simple употребляется в случаях:

1. Если надо рассказать о действии, которое неоднократно / часто (обычно) происходило в прошлом. (My mom always said me...)
2. Если действие произошло единожды и не относится к настоящему никак. (I was born in...)
3. для описания последовательных действий в прошлом. (Shе made a coffee, took her backpack, put on a jacket and went to school.)

Past Perfect употребляется в случаях:

1. Требуется показать действие, произошедшее перед другим действием в прошлом. (Действие завершилось до начала другого).
2. Действие завершилось до определённого момента в прошлом. (I had done my homework before my mom returned.).