Anchor: Sea temperatures vary between 18?? and 24?? C (64 75?? F).
Entailed: Sea temperatures range between 18° and  24° C (64°-75° F)
Contradiction: Sea temperatures are seldom between 18° and  24° C.
Contradiction: Nothing is missing. 
Contradiction: What are you getting at?
Contradiction: The woman is at the store.
Contradiction: He was familiar with the organic parts of the material, but the technical stuff confused him.