A flock of people walking down an ancient street .
A bunch of people walk down the street .
A flock of people walking down an ancient street.
A bunch of people walk down the street.
A bunch of people is the same as a flock of people; a group. If they are walking down they walk down the street.
A bunch of people is the same as a flock of people ; a group . If they are walking down they walk down the street .