The number of people invited _________ fifty, but a number of them _________ absent for different reasons.
__________ has recently been done to provide more buses for the people, a shortage of public vehicle remains a serious problem.
Because Sarah has always saved __________, she is now able to afford a big house.
According to one theory, taking part in high-culture activities makes __________ easy for teenagers to make friends with powerful older people, __________ thus increases the chances of their lives turning out well.
There seems to be two causes as I try to figure out __________ that prevents so many children from being as happy as before.
We were struck by the limited use __________ their natural resources.