canuckseo - 6:02 pm on Jan 8, 2013 (gmt 0)

Both - I use variations of the same term (IE cat, feline, etc) as well as completely different terms (pet, family member, dog, as well as cat breeds). Try and think of the different ways people will search for cats and use those variations of the term.

as for sentences - i've used them on my blog posts but I prefer to use a mixture of anchor text as well as things like linking on the phrase "in my last article"