Answer:
Witnessing the man being killed on TV made Montag trembled.
Step-by-step explanation:
"Fahrenheit 451" is a dystopian novel penned by Ray Bradbury. The novel picturized a society in which books were banned and the people of the society were taken over by the imagination displayed on TV and media.
In the third part of the novel, 'Burning Bright' the protagonist, Guy Montag, decides to fight back the evil of this dystopian society. For his rebellion, he was punished by letting a mechanical hound after him too kill him, but Montag managed to escape society.
He landed at a place where Granger with other fellows was. The chase for Montag was televised over many televisions. A fake killing of Montag was televised by the announcer in which a man who was out for a walk was killed. The headlines flashed saying that Montag has been killed, the traitor.
This news made Montag trembled. It shook him so much that after witnessing the man being killed on TV he gazed at the blank screen of TV without saying anything. he trembled at the thought of the evil of the society. Granger turned to Montag and ironically welcomed him back to life.