It took __________ building supplies to construct these energy-saving houses. It took brains, too.
The country life we ______. The differences between rural and urban areas are disappearing.
The boy likes to play tricks ____ girls, and his parents should cure him ______ that bad habit.
Many of them turned a deaf ear to his advice ______ they knew it to be valuable.
The discovery of new evidence led to ________.
______ late, he also forgot his books.