11.   Using a sharp knife, peel the celery roots so no trace of the rough brown outer covering remains.

12.   Zirconium is used in nuclear reactors to provide the cladding, or outer covering, for the cylindrical fuel rods that power a nuclear reaction.

13.   A German company won a contract Monday to build the outer covering of a giant millennium dome near London, setting off a political storm.

14.   Some pulled out knives, and like hunters skinning prey, stripped away at the outer covering that was supposed to make the aircraft nearly invisible to radar.

15.   Lee and Smith patched up some tears in the outer covering of the telescope using wire and clips as makeshift bandages.