这些牧羊犬非常擅长把羊群赶回羊圈。

These ___sheepdogs are excellent at herding the flock back into the pen.

那位老员工像牧羊犬一样守护着团队里的年轻人，确保他们不会犯错。

The senior employee acted like a ___sheepdog for the young team members, making sure they didn't make mistakes.