The 'Professor' knew too much. How did he prove himself?

The ‘Professor’ knew too much. How did he prove himself? Fill up the space with suitable examples from the story, using the given clues:
(a) about muzzle velocity …
(b) after a thirty mile walk …
© his salute on payday …
(d) the loud sound of a high flying invisible aeroplane …
(e) about hand grenades …
(f) during cookhouse duties …

(a) When the Sergeant mentioned that the muzzle velocity, or the speed at which the bullet leaves the rifle, was “well over two thousand feet per second”, the ‘Professor’ corrected him by giving the exact value (as given in military manuals) as “two thousand, four hundred and forty feet per second”.
(b) After a thirty mile walk, he was not at all tired and also displayed his heartiness by saying, “What about a song, chaps?”
(d) The ‘Professor’ could unmistakably identify the air plane by the harsh engine note due to the high tip speed of the air screw.
(e) The ‘Professor’ gave very specific information (forty-four) about the number of fragments of the outside of a grenade.
(f) During cook house duties, he protested against the unscientific and unhygienic method of peeling potatoes resulting in a sheer waste of vitamin values.