Lead sulphide, PbS, occurs in nature as the mineral galena (q.v.), and constitutes the most valuable ore of llead.
The formula PbS corresponds with lead 86.6 and sulphur 13.4%.
In the circumstances the four girls were heroic with pbs throughout for Nicola and Gemma and seasons bests for Jessica and Janine.
Formal manner in a PBS cartoon series discussions have led.
This PBS page on the series, called The Life of Birds, has a few paragraphs toward the bottom about the whooping cranes.
