Teacher: You are given two sentences. You have to find if there is entailment or agreement of the Hypothesis by the Premise. From the given pair of sentences, you should identify if there is enough information in the Premise to support the claim made in the Hypothesis. The Premise may not exactly be the same as Hypothesis. Your task is to return 'entails' if the premise supports hypothesis else return 'neutral'.
Teacher: Now, understand the problem? If you are still confused, see the following example:
Premise: Lyme Disease is caused by a bacterium that's transmitted by tick bite, but many infected people don't remember a bite. 
 Hypothesis: Lyme disease is caused by bacteria.
Solution: entails
Reason: The premise sentence agrees with the hypothesis that Lyme Disease is a bacterium. The premise also gives additional information about Lyme disease. Therefore Premise entails Hypothesis.

Now, solve this instance: Premise: These valves open and close depending on the phase of the heart beat to allow the blood to flow from one chamber of the heart  to another and to prevent the backflow of blood. 
 Hypothesis: Heart valves prevent the backflow of blood from happening in the heart.
Student:
entails