Anchor: A group of people sit on a long bench while children play on the stairs behind them.
Entailed: A group of people sit together
Contradiction: A group of people dance at a party
Contradiction: Two children play on the swings.
Contradiction: I am not sure what all the effects of chemicals on grass would be. 
Contradiction: the people are in a sailboat.
Contradiction: The book sold well dues to good marketing and a simple message.