Se chocan
We use “se” because you are referring to a group of passengers. Se is used for “they” when the group is plural or singular third person.
We use “chocan” because they are bumping into other passengers which is plural. Chocan is for plural.
Fill in the blanks using the correct form of the verb in parentheses.
Bold answers
6. Tú necesitas gafas nuevas.
7. Yo canto muy mal.
8. Rafael pinta muy bien.
9. ¿Ustedes buscan la avenida Central?
10. Enrique siempre invita a toda la clase a sus fiestas.
Hope this helps!