In what period does the common ancestor of the crustaceus species of the montanian period appear

Define the apical impulse and describe its normal location, size, and duration. which abnormal conditions may affect the location of the apical impulse? explain the mechanism producing normal first and second heart sounds. describe the effect of respiration on the heart sounds. describe the characteristics of the first heart sound and its intensity at the apex of the heart and at the base. describe the characteristics of the second heart sound and its intensity at the apex of the heart and at the base.

The earth formed roughly 4.5 billion years ago, yet evidence of life dates back to about 3.5 billion years ago. which one is not a possible hypothesis of how life on earth arose?

Earthquakes a.created the rock in arches utah b.can be caused by volcanic eruptions c.are caused by tsunami waves d.wear mountains down into hills