I'm not an expert, but I believe the answer is... By the way, feel free to correct any changes on what I answered.
The party was almost ruined by the rain last Saturday. When the rain approached, we all grabbed what we could.
"We better hurry," Mandy said, "or we'll get soaked.".
Joe picked up the cake and I said, "I've got the cake.".
"You should get the sandwhiches," yelled Theodore as he picked up the potato salad. We all made it under the gazebo as the first rain drops fell.
Answer:
decided to carefully review his novel to see if there was anything he could salvage
Explanation:
The predicate of a sentence is simply the action verb and which shows or explains something about the subject of the sentence.
Therefore, the complete predicate of the sentence given is "decided to carefully review his novel to see if there was anything he could salvage".