Question:
Based on the premise "A particular strength of such studies is the fact that potential confounding variables such as socio-economic status, occupation, and smoking do not vary on a day-to-day basis in an individual area.", can we conclude that "The same amount of people smoke in Boston each day."?
****
Answer:
it is not possible to tell

Question:
Based on the premise "How? demanded Tuppence, opening her eyes very wide.", can we conclude that "Tuppence doesn't have eyes. "?
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Answer:
no

Question:
Based on the premise "Sir James rose to his feet.", can we conclude that "Sir James stood on a carpet. "?
****
Answer:
it is not possible to tell