Anchor: A person wearing a helmet and pads is riding a dirt bike and jumping over a log.
Entailed: there is a person out for a bike ride on a dirt road
Contradiction: there is a person driving a car on a dirt road
Contradiction: An adult and a child fence in an arena.
Contradiction: There are cars on the snowy street.
Contradiction: Poirot said yes. 
Contradiction: Drummers march.