A flock of sheep is walking back and forth on the grassland.

一群羊在草原上来回走动。

I saw a flock of sheep when the car passed through a village.

当汽车行经村庄时，我看到了一群羊。

They raised a flock of sheep.

他们养着一群羊。

A flock of sheep blocked the road.

一群绵羊挡住了道路。

He keeps a flock of sheep.

他养了一群羊。