cattle是单数还是复数

请看下面一题：In fact,_______ one cause that leads to the problem.A.cattle is B.cattle areC.cattles are D.the cattles are【陷阱】此题容易误选A,想当然地认为cattle是单数,并且空格有表单数的one,自然谓语动词用is.【陷阱】其实,正确答案为B.cattle(牲畜,牛)为集合名词,尽管它不带复数词尾-s,却永远表示复数意义,若用作主语,谓语要用复数.又如：For this many cattle were killed.为此宰了不少牲畜.The *ers were herded like cattle.囚犯像牲口一样被赶到一起.类似地,police(警察),people(人),police(警察),poultry(家禽)等也具有同样用法,即只有单数形式,但却表示复数意义；用作主语时谓语通常也用复数；不与 a(n) 连用,但可与the连用(表示总括意义和特指).如：The poultry have been fed.家禽已经喂过饲料了.In Britain police do not usually carry guns.在英国警察通常不带枪.