Anchor: For the Menidia beryllina test method, the effluent sample was an industrial wastewater spiked with CuSO4, the receiving water sample was a natural seawater spiked with CuSO4, and the reference toxicant sample was bioassay-grade FORTY FATHOMSa synthetic seawater spiked with CuSO4.
Entailed: Once the solution is spiked with CuSO4, the subsequent tests always showed a spike in CuSO4.
Contradiction: There were reports of the solution causing side effects. 
Contradiction: A man walks down the street.
Contradiction: Addressing computer based threats has proven to be challenging.
Contradiction: The referee calls a strike.
Contradiction: Shouldn't your friends already be here?