Dogs are thought to be easier to train than cats, but this
may be because they evolved to hunt in packs,
cooperate with other dogs and be obedient (15)---- a
leader. Their memory requires constant reinforcement,
(16)---- they quickly forget. Nonetheless, they are often
(17)---- simply by giving them the attention they need. On
the contrary, cats evolved to hunt solo and are much
more devious. In some cases, they (18)---- but do not
have the dog’s desire to please. There is some
evidence that cats remember specific events longer
than dogs do, but (19)---- their excellent memory for
people and spaces, both species are able to build
complex mental maps of their surroundings and find
their way home.