n.骑兵(队)
I am a soldier of the fourth cavalry. 我是第四骑兵部队的一员。
They were taken in flank by a troop of cavalry. 他们的侧翼受到一队骑兵袭击。
cavalry是集合名词，用作主语时，如侧重整体谓语动词用单数形式，如侧重个体谓语动词用复数形式。
n.骑兵
骑兵
