There are a number of veins and arteries attaching to the heart. The superior and inferior vena connect to the right atrium, while the pulmonary veins connect to the left atrium. The pulmonary artery connects the right ventricle to the lungs, while the aorta connects the left ventricle to the body.
This H+ ion gradient is referred to as a proton motive force. It is created using energy from the Krebs cycle in the matrix of the mitochondria. As electrons are passed from one protein complex to another, reducing molecules such as NADH and FADH2, the protons are pumped to the intermembrane space of the mitochondria. ATP synthase uses this potential to generate ATP as the H+ ions move downgradient (back to the matrix) through channels in the protein enzyme.
For the first question, we know that the water transformed into a gas. This fact eliminates choices C and D, primarily because they describe the change as "gas to liquid" instead of liquid to gas.
What separates B from A is that B is saying the liquid changed to a gas in response to sunlight, which is completely false and impertinent to the prompt.
A is the correct answer.
For the second question, we know that condensation causes clouds -- and that neither evaporation nor water vapor would clear clouds to make more of them, which eliminates choices B and D. Going back to condensation, the accumulation of water vapor plays a big role in the formation of clouds. While evaporation does play a part in [it] as well, condensation is what caused the sudden appearance of clouds in the troposphere.