Answer:
PVR is calculated by the formulae: 
Explanation:
Pulmonary vascular resistance may be defined as the resistance to blood through the pulmonary circulation.
PVR can be determined by the following formula:

Here, PAP is the pulmonary artery pressure, PAOP is pulmonary artery occlusion pressure and CO is cardiac output.
Investigating cricket will reveals that some specie of the insect produce a song by rubbing their legs or wings against each other. In those specie that sing only the male insect produce songs.
This observation can be taken to mean that the male song is a potential form of communication to potential mates.
Answer:
Explanation:
Colour of objects. The colours we see are the wavelengths that are reflected or transmitted. For example, a red shirt looks red because the dye molecules in the fabric have absorbed the wavelengths of light from the violet/blue end of the spectrum. Red light is the only light that is reflected from the shirt.