Answer: D
Explanation: when gasoline is burned by the car, it releases gas which pollutes the air.
<span>Cyst formation in a paramecium enables genetic exchange by conjugation.</span><span>
Through the reproduction of cysts, the survival of brine shrimps increase even when dealing in extreme conditions. The cysts can remain in total stasis for two years in oxygen less surroundings, they can survive freezing temperature and boiling tempreture. When conditions improve and eggs are placed in salt water, they hatch within a few hours and increase the population of brine shrimps. </span>
<span>Rh-positive fetus and an Rh-negative mother condition occur.</span>
Ventricular systole is when the ventricles of the heart as the result of electrical activity which helps to pump blood. During ventricular systole oxygenated blood is pumped from the left ventricle through the aortic valve and aorta. Simultaneously deoxygenated blood is pumped from the right ventricle through the pulmonic valve and pulmonary artery to the lungs. Using this explanation blood enters the aorta and pulmonary artery during ventricular systole. <span />
