Ineed to know the complete verb and the participle

Based on your knowledge of word parts what does the word intervene mean

20 points plus brainlest answer if right.joe nesbo, a travelling salesman, was staying at a hotel for business. he was having a dinner meeting that night, so he decided to take a nap in the middle of the afternoon. he was awakened by a knock at the door, and then a man walked in. “oh my, i’m terribly sorry, this isn’t my room. , pardon the intrusion.” the man calmly backed out and left. nesbo got up and locked the door – something he forgot to do before his nap – and lay back down on the bed. but then he shot up in bed and called the lobby to tell them there was a burglar on the prowl. what made nesbo think that?

How does gregor change from the beginning to the end of the story?