11.   Business people who want to test the idea of a mental workout can do so easily without calling in a consultant.

12.   But until it develops some theories, it will not be able to test new ideas about how living systems are organized.

13.   Dr. Pierre Rollin, of the Special Pathogens Branch at the federal Centers for Disease Control, said the work would help researchers test ideas.

14.   Each offered him planes at no cost to test his idea for all-electric flight.

15.   He and others are thinking of testing this idea in the event of a large outbreak.

16.   He even went so far as to use a lawn sprinkler to simulate rain to test his idea under various weather conditions.

17.   He has already tested this idea with rats.

18.   He invites executives to meet and dine at the National Palace and phones them at odd hours to test his ideas about fiscal recovery.

19.   He was building a radio antenna to test that idea when two other investigators, Drs. Robert Wilson and Arno Penzias, discovered the echo by accident.

20.   Here, a worker tries out a new way to make hydraulic reservoirs by testing his ideas in foam and wood.