a group of sheep的用法和样例：
- The group of sheep is lead by a strong ewe.
- Those two brave girls have rescued out a group of sheep from the snowstorm.
- A group of boys dashed out of the classroom.
- I come upon a group of children play in the street.
- Beside this picture with profusions of colors, a group of sheep are lowing their heads, eating by the river bank.