Question

what makes human brain sharp

Answer 1

Answer:

Their is only way i.e. use of brain regularly and after some days your brain will become sharper.

Otherwise you can use medicinal drugs

Answer 2

A positive thinking ability and regular solving of challenging questions would help in making brain sharp.

If it is just a riddle, then my answer would be by knife and blade. But unfortunately the person won't survive that time.

HOPE THIS COULD HELP