On film, large dogs seem powerful, but their size decreases their ability to use oxygen efficiently.
在电影里，体型巨大的狗狗看似强壮，但其实它们的体型降低了其利用氧气的能力。
In competitive dog-sledding, dogs usually weigh less than 55 pounds and can comfortably trot over 70 miles a day.
在雪橇犬的竞技中，通常体重不到55磅的狗狗每天可轻松跑70英里。
A sled dog also needs the right temperament. They must love running and be sociable and obedient.
雪橇犬的性情也得温和。它们必须热爱奔跑，友善且温顺。
Like wild dogs, each team has a hierarchy, but the dogs struggle for position by taking aggressive or submissive postures such as squealing and rolling.
和野狗一样，每个队伍都有等级制度，不过雪橇犬会采取侵略性或顺从的姿势来争夺位置，比如尖叫和滚动。
Real dogfights are rare because the dogs are carefully introduced and trained before going out on the trail.
它们混战的机率很小，因为它们在进入雪橇队前接受了良好的引导和训练。
The careful crossing of northern dogs, like Malamutes, with southern breeds like Greyhounds produces dogs with the right stuff to be sled dogs.
爱斯基摩狗等北方品种与长腿猎狗等南方品种交配得当的话，他们的后代将具备成为雪橇狗的优良基因。
译文为秀哈英语翻译，未经授权请勿转载!
