— Where is John? — He _____ in the library.
10、______ of the land in that district ______ covered with trees and grass.
9、The number of people invited ______ fifty, but a number of them _____ absent for different reasons.
8、When and where to go for the on-salary holiday ______ yet.
7、Every possible means ______ to prevent the air pollution, but the sky is still not clear.
6、Books of this kind ______ well.