The number of people at present ______ sixty, but a number of people______ coming here to get tickets for free.
It is difficult for us to learn a lesson in life __________ we’ve actually had that lesson.
__________ he had not hurt his leg, John would have won the race.
I won’t call you, __________ something unexpected happens.
He was told that it would be at least three more months __________ he could recover and return to work.
Most birds find it safe to sleep in the trees, but __________ they have eggs or young chicks, they don’t use a nest.