Answer:
<em>Earth's gravity pulls air as close to the surface as possible. ... As altitude increases, the amount of gas molecules in the air decreases—the air becomes less dense than air nearer to sea level. This is what meteorologists and mountaineers mean by "thin air." Thin air exerts less pressure than air at a lower altitude.</em>
Answer:
The center of the Milky Way most likely contains a supermassive black hole.
Explanation:
Because it is an eleptical galaxy, it has a little rotation to it but not enough to flatten out so the center will contain a supermassive black hole.
Answer:
Noise level will be -18.2 watt
So option (b) will be correct answer
Explanation:
We have given sound intensity 
And threshold intensity 
( in question it is given as 
but its standard value is 
)
Now noise level 
So the noise level will be -18.2
So option (b) will be correct answer
