Улицы, по которым он проходил, были

Улицы, по которым он проходил, были узкие и грязные

Результаты (английский) 1:

The street on which it was held, were narrow and dirty

Результаты (английский) 2:

Streets through which he passed, were narrow and dirty

Результаты (английский) 3:

The street on which it took place, were narrow and dirty