What is the name for a disturbance that removes most of the organisms and damages the soil? A. Cyclical disturbance
B. Secondary disturbance
C. Primary disturbance
D. Small disturbance

the answer is: they occur when the sun, moon, and earth are aligned. in spite of their name, these tides occur twice a year in the spring and fall.

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.

links? do you have a link? i don't see anything?