a group of 作主语怎么用

1.A group of kids were playing with a ball in the street.一群孩子在街上玩球。 2.A group of noisy children tumbled out of the bus.一群吵吵嚷嚷的孩子一窝蜂地下了公共汽车。 3.A group of downcast men stood waiting for food...