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13. Is the last statement true or false?
  All socks are pencils. All pencils are forks. Some forks have a long nose.
Therefore, it can be said with certainty that some socks have a long nose.

False. Forks with a long nose are not necessarily pencils. If some of the long-nosed forks are pencils, it is not obligatory that they can be socks. As a result, the last statement is not exact.