Is the premise "Two people in red shirts are sitting in a lifeguard chair on a beach with an American flag flying behind them." true if "Two lifeguards at work on the beach."?
it is not possible to tell
Is the premise "two men on bicycles on the side of a snowpacked road in the country" true if "Two men indoors."?
no
Is the premise "Two youths walk down an inclined street." true if "People are walking downhill."?
yes
Is the premise "A surfer riding a large wave" true if "A person surfing."?

yes