The gap between rural and urban education in China is widening, and education is the key to _____ rural problems.
Is this the piano _______ your familoy for over eighty years?
After he won all the money they treated him ______a king.
They treated her very well _______one of the family members.
Tom received an invitation from Carrol but he ______.
He picked up an envelope ____50 dollars in it.