He was _____ by his grandparents, so his parents seemed to be strangers to him.
He will give us a report on how to study English well, but when and where ________.
We should work together to build a society for kids, ________free from war and violence.
He slipped(溜进) into the classroom without ___________.
This special strain of rice makes _________ possible to produce one third more of the crop in the same fields.
---Is that the small town you often talk about?---Right, just the one ______________ you know I used to work for three years.