1.   If a steady stream of fresh brain cells is continually arriving to be incorporated into new circuitry, then the brain is more malleable than hardly anyone has realized.

2.   New electronic circuitry was necessary, too, to replace analog VCRs with digital models.

3.   The projector uses some fancy new circuitry that promises a bright, clear picture in any normally lit room.

4.   Voluntarily installing new circuitry to check on pilots is a first for Boeing, and other aviation experts could not recall such a step by another manufacturer.