GEI-2 UNIT 3 GRAMMAR

The lights in the sky were too bright to be from regular airplanes. They ____ been caused by something unusual.

The villagers noticed strange footprints near the forest. They ____ belonged to an animal because they were too large.

Some villagers think the lights ____ been a natural phenomenon, but others believe it was supernatural.

The explorers didn't return for days. They ____ gotten lost in the dense forest.

The loud noise during the lights' disappearance ____ been caused by thunder because the sky was clear.

The missing villagers returned with no memory of what happened. They ____ experienced something traumatic.

The lights vanished suddenly and left no trace. They ____ been caused by a machine, as no debris was found.

Some villagers believed the lights were a sign from the spirits. It ____ been just a coincidence that the crops failed afterward.

Scientists visited the village but found no scientific explanation. They ____ overlooked some critical evidence.