In which part does gaseous exchange take place in a rabbit?

The partial pressures (in $mm \ Hg$) of oxygen $(O_{2})$ and carbon dioxide $(CO_{2})$ at the alveoli (the site of diffusion) are:

Partial pressure for oxygen and $CO_2$ is represented as

Water vapor exits from the leaves of terrestrial plants through open stomata. During photosynthesis,carbon dioxide enters the plant through the same open stomata. Identify the reason for the above statements from the following options.

Blood leaving the lungs is rich in:

Explain the exchange of gases in short.