There is one row of teeth in the lower jaw and this fits between the two rows in the upper jaw when the animal chews.
ðɛɹ ɪz wˈʌn ɹˈoʊ ʌv tˈiːθ ɪnðə lˈoʊɚ dʒˈɔː ænd ðɪs fˈɪts bᵻtwˌiːn ðə tˈuː ɹˈoʊz ɪnðɪ ˌʌpɚ dʒˈɔː wɛn ðɪ ˈænɪməl tʃˈuːz.