Text: Concealed and protected against atmospheric changes for 17,000 years, these awe-inspiring frescoes and engravings of bulls, horses, ibex, bison, and deer were discovered by four teenagers chasing a dog in 1940.
Entailment: While four teenagers were chasing a dog in 1940, they stumbled upon ancient frescoes and engravings that have been concealed for the last 17,000 years.
Contradiction: The 17,000 year-old frescoes and engravings were subject to rain, wind, and other atmospheric changes that made them difficult to identify.