The limbs are in two pairs-an upper pair, called the arms, and a lower pair, called the legs.

上面的一对称为胳膊, 下面的一对则是腿。

The expert lowers cautiously a pair of crab-claws--open-springed iron jaws at the end of a twelve-foot pole--and strikes the crab dexterously.

专家小心翼翼地放下一对蟹钳——一根十二英尺长的杆子末端有张开弹簧的铁爪——灵巧地击打螃蟹。