I think whoever gave you this riddle messed it up. It should be a million years, and the answer is the letter "t"
The letter M.
The letter M.!
The letter M.
The letter "Y."
The letter 'm'.
It should be 'occurs' and the answer is the letter M.
The letter "m" :DOnce in a minute, twice in a moment, and never in a thousand years.
an m
M
The letter M
The letter 'm' !
M!
M!
You mean 'once in a minute, twice in a moment. but not once in a thousand years. Answer is the letter 'm'
The letter m.
Letter M
M