Question

I went to Rebecca's house, but she wasn't at home. She____out left was looking had gone were tidying had forgotten had left went

Answer 1

I went to Rebecca's house, but she wasn't at home. She had gone out

Тоже самое что и в прошлом, тут действие произошло до действия в прошедшем, то есть используем past perfect:

had gone

had forgotten

had left

Из этих трех лучше всего подходит: had gone

Answer 2

The correct answer is: "had gone out."

So the complete sentence would be: "I went to Rebecca's house, but she wasn't at home. She had gone out."