In this task, you are given a paragraph, and your job is to generate comma-separated entities present in the given paragraph. Generate entities from a given passage in such a way that (i) they are present in the paragraph, (ii) they are non-duplicate, (iii) they underwent a state change during the process. Avoid creating entities that (i) aren't present in the process paragraph and (ii) aren't significant. 

Oxygen-depleted blood enters the heart on the right atrium. The atrium contracts. Blood flows from your right atrium into your right ventricle through the open tricuspid valve. When the ventricle is full, the tricuspid valve shuts. The ventricle contracts. Blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs. The lungs oxygenate the blood. The oxygenated blood goes into the left atrium. The left atrium sends the blood throughout the body. 
oxygen-depleted blood ; blood ,oxygenated blood ; blood 

During evaporation the sun heats up water in rivers or lakes or the ocean and turns it into vapor or steam. The water vapor or steam leaves the river, lake or ocean and goes into the air. Water vapor in the air gets cold and changes back into liquid, forming clouds, which is called condensation. Precipitation occurs when so much water has condensed that the air cannot hold it anymore. Water falls back to the earth in the form of rain, hail, sleet or snow. When water ends up on land, it will either soak into the earth and become part of the "ground water" for animals or plants to drink. It may also run into the oceans, lakes, or rivers where the cycle starts again. 
water ,vapor; steam; water vapor ,clouds ,rain ,hail ,sleet ,snow 

Carbon dioxide from the air passes through small pores (holes) in the leaves. These pores are called stomata. Water is absorbed by the roots. It passes through vessels in the stem on its way to the leaves. Sunlight is absorbed by a green chemical in the leaves. 

carbon dioxide ,water ,sunlight