Most simple utilities will open the file and read (all the way) through it. If this is a plain text file and you know the line numbers of interest in advance, something like this will work
sed -n '105,20000 p ; 20000q' input.file > output.file
Adjust line numbers accordingly - the "20000q" stops it reading any further; saves all the unnecessary I/O reading to end of file.
If you wanted to do (say) three at once without re-reading the file, try this
sed -n -e '105,20000 w file1.out' -e '50000,60000 w file2.out' -e '80000,90000 w file3.out' -e 90000q input.file
Note the adjustment to the finishing line number.
These can also be passed as shell variables (use double quotes, not single) - any more than this probably needs some coding "smarts"; awk or perl.