How is a lake or river that freezes over to the organisms in the water?

What must be done to breed dogs for a partical trait

When a gasoline engine burns gasoline, what type of chemical reaction is occurring?

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.