試題詳解

25.In which of the following does the (a)-sentence NOT entail the (b)-sentence?
(A) (a) X is a cat. (b) X is an animal.
(B) (a) X is a cat. (b) X is a quadruped.
(C) (a) All dogs are purple. (b) My dog is purple.
(D) (a) X is a cat. (b) X has four legs.