Circulation begins when blood returning to the heart from the pulmonary vein enters the left atrium. a. cardiac b. pulmonary c. systemic d. secondary

the water is warmed up by the sun and then it evaporates into the atmosphere. the sunlight warms the water by its heat. water is then cooled down and condensation takes place. the water then finally returns back to the earth by the process of precipitation in the form of rain or ice.

explanation:

flooding wildfire landslides climate change the factors listed have an immediate effect on the animal populations found in any habitat. the four factors would lead to a death. b emigration. eliminate c immigration. d mutations.

d. organisms have cells with different shapes and functions.