Definition: In this task, you're given two sentences. Indicate if the first sentence clearly entails the second sentence (i.e., one can conclude the 2nd sentence by reading the 1st one). Indicate your answer with '1' if the first sentence entails the second sentence, otherwise answer with '0'.
Input: Sentence 1: World health officials warned yesterday that West Africa and Central Africa were on the verge of the worst polio outbreak in years, stemming from the refusal of a single state in northern Nigeria to vaccinate children against the disease. Sentence 2: African polio outbreak feared

1