英语翻译The bodies of dwarf individuals of mammalianspecies are generally smaller in relation to those ofnondwarf individuals than are the teeth of the dwarfindividuals in relation to those of the nondwarf indi-viduals.这个 in relation to 是怎么个用法啊？还有than 后面为啥跟着个are

英语翻译
The bodies of dwarf individuals of mammalian
species are generally smaller in relation to those of
nondwarf individuals than are the teeth of the dwarf
individuals in relation to those of the nondwarf indi-
viduals.
这个 in relation to 是怎么个用法啊？
还有than 后面为啥跟着个are