sheep可数还是不可数用is还是are

The path was no better than a sheep track.

那条小路简直就像是羊肠小道。

Stefano used a motorcycle to herd the sheep.

斯蒂芬诺骑一辆摩托车驱赶羊群。

Competitors have six minutes to shear four sheep.

参赛者们有6分钟的时间来给4只羊剪毛。