11.   Not yet understood is why CFS sufferers have insufficient blood volume in the left ventricle, inappropriate neural responses or both.

12.   Stroke specialists say that public understanding is critical if TPA is to become a more common treatment.

13.   That understanding is particularly important when they first become eligible for Medicare.

14.   Understood here are the meticulous workings and mysterious organizing principles that make Debussy tower over his reputation as an exotic.