All of the statements about the nitrogen cycle are true except one. that is

a) lightning breaks nitrogen molecules so it can combine with oxygen.
b) putting man-made fertilizers on farm fields exceeds natural nitrogen levels in the soil.
c) bacteria located in the soil trap excess nitrogen and to remove it from plant roots.
d) although nitrogen is the most abundant atmospheric gas, plants cannot use it from the air.

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.