Just as the tree is the unit of a forest and the book the unit of a library, ______ the molecule is the unit of matter.
In my opinion, learning is endless and the more knowledge you get, __________.
Thirty percent of the cattle __________ thin, but the rest __________ fat.
__________ of the land in that district __________ covered with trees and grass.
With great pain, the wounded soldier __________ to his feet and went on fighting.
At first, our company was very small, but after purchasing some smaller ones, it soon __________ into a large one.