As a parent, you ought to set a better _____ to your children, who learn bad behaviors quickly.

Many countries are increasing their use of natural gas, wind and other forms of ______.

The faces of four famous American presidents on Mount Rushmore can be seen from a ____ of 60 miles.

The dentist gave me a shot which took ________ almost immediately and I didn't feel a thing.

Radar enables the pilot of an airliner to take off, fly and land in _____.