Owing to over-drinking.his health is ____.
Books of this kind ______ well.
Professor Smith, along with his assistants,____ on the project day and night to meet the deadline.
_____ of the land in that district _____ covered with trees and grass.
The company had about 20 notebook computers but only one-third _______ used regularly. Now we have 60 working all day long.(2006浙江)
The country life he was used to ______ greatly since 1992.