When the traffic lights are red, we _______ stop.

A left－luggage office is a place where bags ________ be left for a short time，especially at a railway station.

There _____ be any difficulty in passing the road test since you have practised a lot in the driving school.

She ______ have attended that meeting, for she was doing paperwork in the office then.

If you don't know the word, you can _____ in the dictionary.