Anchor: N, the total number of LC50 values used in calculating the CV(%) varied with organism and toxicant because some data were rejected due to water hardness, lack of concentration measurements, and/or because some of the LC50s were not calculable.
Entailed: Certain variables caused some data to be rejected.
Contradiction: The model was developed to prevent any data from being rejected.
Contradiction: Richardson has a bad reputation and I know that.
Contradiction: They serve great lobster.
Contradiction: A young boy  and old lady walking towards the marked ground.
Contradiction: Two men talk to eachother.