Fill in the gaps using the word in the brackets. These sentences are in the past perfect.
After they ____________________ (eat) the shellfish, they began to feel sick. After they had eaten the shellfish, they began to feel sick.
1. We went out when we (finish) our dinner.
2. We were late for the plane because we (forgot) our passports.
3. The grass was green because it (rain) all summer.
4. You (study) for the test, so you weren't nervous.
5. We could go to the concert because we (bring) our tickets.