Fill in the Blanks (Reading & Writing)

Railway timetables must —allow forallow ofallow withallow sufficient buffer time between services, since even minor delays can quickly cascade across a busy network. Planners typically build in extra minutes at major junctions, where trains from several —connectingconnectiveconnected toconnection routes converge. Without this margin, a single late departure could —severelysevereseveritysevereness disrupt an entire day's schedule.