11.   The Saharan dust that moved over our area Wednesday is bound to remain over our area at least through Friday with a gradual decrease afterwards.

12.   These swells will begin a gradual decrease by tomorrow.

13.   Therefore, a gradual decrease in clouds and showers tonight and Monday should be anticipated.

14.   The accord, which has been the subject of long and delicate negotiations, envisions a gradual decrease in trade barriers.