What makes a nicotine substitute effective?

Astructural difference between the trachea and esophagus that prevents the trachea from collapsing is the presence of: a) smooth muscle b) skeletal muscle c) respiratory cilia d) rings of cartilage

The only infectious disease that was a top-ten killer of americans in 1900 that is still a top-ten killer in 1990 is hiv/aids select one: true false

Being is not a situational factor common to adults who commit violent acts against children.