The scientist Galen advanced understanding of Anatomy
Astronomy
Geometry
Archectecure

Anatomy

Explanation:

Galen contribute tremendously to the understanding of the respiratory system, blood and the circulatory system.

to protect the united states' role as a world leader, president truman wanted to prevent the soviet union from spreading communism beyond its post-world war ii boundaries. he declared that the united states must assist any nations struggling to prevent a communist takeover.

an expansion is one of two basic business cycle phases; the other is contraction. the transition from expansion to contraction is a peak, and the changeover from contraction to expansion is a trough.