18.Everyone must have known the death of the waitress, __________?
As a result of destroying the forests, a large __________ of desert __________ covered the land.
__________ of the land in that district __________ covered with trees and grass.
Every boy and every girl as well as some teachers who __________ to visit the museum __________ asked to be at the school gate before 6:00 in the morning.
More than one student __________ absent. The number of students present __________56.
Large quantities of water, as well as some other timely help,__________ since the serious drought hit Yunnan Province.