The pleural cavity contains a little amount of liquid called as "pleural fluid".
<u>Explanation:</u>
The two thin serum producing membrane which gathers back itself resulted in membrane cavity of two layer pleural sac, which surrounds the lungs is termed as "pleura".
This cavity contain small amount of liquid named as pleural fluid, its function is to provide lubrication during respiration when the lungs expand and contract. Most fluid is generated via bulk flow through the parietal circulation and is reabsorbed by the lymphatic system.
Thus pleural fluid is continuously produced and reabsorbed. A few millilitres of pleural fluid is always present inside the intrapleural space in a typical 70 kg human.
None of the choices is correct.
Satellite communication is quite effective using either analog OR digital transmission.
Sound can't be used for satellite communication at all. (There's no medium to carry the sound to or from the satellite, and if there were, then the round-trip up and down through a geostationary satellite would take at least a minute at the sea-level speed of sound.)
Cellular devices can work but aren't required.
Isn't velocity Distance over time? if the degree isn't adding resistance it should be 4000 ÷ 20 which gives you 200mps ("per second") which is the velocity without resistance.
