VOA慢速英语:'An Occurrence at Owl Creek Bridge' by Ambrose Bierce

swift - adj. moving or able to move very fast

scream - n. a loud and high cry or sound​

cannon - n. a large gun that shoots heavy metal or stone balls and that was once a common military weapon

whirlpool - n. an area of water in a river, stream, etc., that moves very fast in a circle​