group of+（数字）中group要加s吗?

group of+（数字）中group要加s吗? group of group group: Group Group one group of a group of be a group of 中be是is 还是are? a group of man 还是a group of men 为什么？ a group of enemies or ,a group of enemy 用a group of 造句. a group of 中文意思 a group of classmates是什么意思 A group of young birds! a group of 怎么用 [英译汉]---One group denies the humanity of the other group. group+数字 数字是放前还是后