Stop cutting trees, ________ the earth will become worse and worse.
–Would you like another sandwich? --Another sandwich? I _____ my first one yet.
Many experts hold the view _____ teacher development is ____ the key to better education lies.
_____ that he has no qualifications in business management, Ken plans to gain the necessary skills by taking a part-time course.
The river _____ banks used to be covered with fruit trees and flowers is now seriously polluted.