Từ còn thiếu trong đoạn văn là "suburbs."

Đoạn văn hoàn chỉnh sẽ như sau:

"By seven o'clock in the morning, the streets are filled again with people. Millions of people live in the big city, and millions of people who work in the big city live in the suburbs, the commuters, and hurrying to get their offices. Everyone is in a hurry. Some stop only to drink a cup of coffee. Others stop to buy..."