Anchor: However, the water hardness for the sixth laboratory was 255 mg/L, resulting in LC50 values for silver more than an order of magnitude larger than for the other five.
Entailed: The water hardness for the sixth laboratory was 255 mg/L.
Contradiction: The sixth laboratory made no report about the water hardness.
Contradiction: A group of people are riding their bikes on a sunny day.
Contradiction: The Golden Dragon dance is held in the month of March.  
Contradiction: Why didn't you ask the sitter any questions?
Contradiction: A group of people are showering.