sentence: A man sets straw and sticks on top of a bundle of tinder in a fire pit. sentence:  The person picks up a flint and a knife from a chair near by. sentence:  The man sparks the flint using a knife onto the stack of sticks and tinder causing it to ignite. sentence:  The man adds more sticks and bark to the top of the fire. sentence:  The flame gets low in the fire and it begins to smoke before igniting fully again.