Aparticle can infect humans and make them sick. it attaches to a host cell and injects its rna, which the host uses to make proteins for the particle
this particle cannot reproduce on its own and can only copy itself by using the machinery of the host.
which explains whether the particle described is a virus or a cell?

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:

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.