Question

____twenty boys were playing football at that time yesterday. A. Each B.Some C.No one . D.Nei

Answer 1

答案是 B. Some

Some twenty boys were playing football at that time yesterday.
昨天那个时候大概有二十来个小孩在打橄榄球。

Each（每个）和 No one （没有人）在这里用都不适合。

Some + 数字 + 名词 是在英文里一个很通常的说法。意思就是，大概有那么几个人在做某某事情。

如：

Some twenty girls attended my birthday party yesterday.
大概有二十来个人昨天来参加我的生日庆祝会。