Answer:
A) if each astronaut breathes about 500 cm³, the total volume of air breathed in a year is 14716.8m³.
B) The Diameter of this spherical space station should be 30.4m
Explanation:
The breathing frequency (according to Rochester encyclopedia) is about 12-16 breath per minute. if we take the mean value (14 breath per minute), we can estimate the total breaths of a person along a year:

If we multiply this for the number of people in the station and the volume each breath needs, we obtain the volume breathed in a year.
The volume of a sphere is:

So the diameter is:
![D=2r=2\sqrt[3]{\frac{3V_{sph}}{4\pi}} =30.4m](https://tex.z-dn.net/?f=D%3D2r%3D2%5Csqrt%5B3%5D%7B%5Cfrac%7B3V_%7Bsph%7D%7D%7B4%5Cpi%7D%7D%20%3D30.4m)
The planets have (their) moons. So the answer would be planets.
Explanation:
The machine whose efficiency is 100% is known as perfect machine .This machine is not possible in real life because every machine is affected by the overcoming friction due to which is efficiency become less than hundred percent .
When drinking at a private event, you should assume that drinks will be STRONGER THAN NORMAL.
At private events, some hosts have the habit of mixing different drinks together in order to increase the intoxicating power of the drinks. This does not normally happen when one is buying from restaurants or other commercial places. Thus, to be on the safe side, one should always assume that drinks will be stronger when one is attending a private event, this will caution one to drink responsibly in order to avoid intoxication.