问题，高手进来

1.pair可视为和family一样的集合名词(collective noun)，要视为单数还是复数通常视使用者的意念而定（只有指人时，通常视为复数，因为人是单独的个体。所以这里为He have a pair of shoes。。
[参考：The verb form to be used with “pair” depends on whether the elements that make up the pair are considered as mates or as individual items. So it is correct to say, “This pair of gloves is wearing out” [considered as mates] and “The pair of boys are lazy” [considered as individuals]. --Harper Dictionary of Contemporary Usage
“Pair” is one of those collective nouns that take a singular or plural verb according to notional agreement. If you are thinking of the individuals in the pair, you will use a plural verb: A pair of elephants were grazing near the camp . . . . If you are thinking of the pair as a unit, you will use the singular: Genuine crocodile loafers . . . . The handsome pair has a hand-sewn moccasin construction . . . . --Webster’s Dictionary of English Usage
Say “pair is” when that word refers to one entity, and say “pair are” when the word