| 1. | The cows were feeding on hay in the barn . 母牛正在牲口棚里吃干草呢。 |
| 2. | A cow's estrus cycle averages 21 days . 母牛的发情周期平均为21天。 |
| 3. | In-calf heifers are admirable for this work . 怀小牛的小母牛最适合这项工作。 |
| 4. | Sometimes, in the darkness, a cow coughed . 有时,黑暗中传来一阵母牛的喷鼻声。 |
| 5. | His cows got fat and his horses sleek . 她的母牛都上了膘,他的马匹养得毛皮油亮。 |
| 6. | His bull will come to serve our cows tomorrow . 明天我们用他的公牛与我们的母牛配种。 |
| 7. | That cow is a good milk-maker . 那头母牛产奶多。 |
| 8. | It seems that peaceful cows may be unfriendly bulls . 看来温顺的母牛也可能变成凶恶的公牛。 |
| 9. | Cows supply us with milk . 母牛供给我们牛奶。 |
| 10. | Each cow normally produces only one calf at a time . 在一般情况下,一头母牛每次只能产一头牛犊。 |