a head of cattle 可以这样说吗?cattle 不是复数吗那 一头牛是什么

a head of cattle 可以这样说吗?cattle 不是复数吗那 一头牛是什么 200 head cattle ,200 head of cattle ,200 head cattles,200 heads of cattle? 英语表示一头牛：a head of cattle.而head也是头的意思, five head of cattle 还是 five heads of cattlefive head of cattle中head 加不加s? tow head of cattle 中的 head要加s吗five head of cattle 五头牛 对吗 cattle是可数名词吗?如果是,那为什么要用计量词（a head of cattle） 关于cattle 这个单词是“three heads of cattle”还是three head of cattle? six head of cattle head 为什么不是复数? two head of cattle为什么 head 不变复数 two head of cattle,head要加s吗?可是为什么ten head of cattle 又不用加s? 200 head of cattle是还是200 heads of 10 head of cattle 为什么?10头牛 这里的head 理由是不是head与cattle 都是单复数同形? —How many ____ does your uncle have on his farm? —Twenty, I think. A. head of cattle B. heads of cattle C. head of cattles D. heads of cattles Mr Smith bought twenty more head of cattle.这里的head 是否加s Dozens of people have been killed in a cattle raid in Warrap state in South Sudan.这句话中的 cattle cattle,progress,advice在使用时,有没有单复数之分.为什么说是two head of cattle而不是two cattle 5头牛five head of cattle ,head 不用复数啊?书上写 5头牛：five head of cattle 为什么head 不用复数啊?除了表示牛 有这种表达 还有什么动物也这样说啊 ..head of.. He has ___D_ on his farm.A.20 head of cattles B.20 heads of cattles.C.20 heads of cattle D.20 head of cattle.请高手讲下,这个题为什么要选D而不选B呢,我有点不懂,请讲的详细点,我将感激不尽!