瘤牛

例句：

1. 1. The cow was afflicted with a tumor that required surgery.
   这头奶牛患有肿瘤，需要手术。
2. 2. The farmer had tocull the cows toprevent the spread of disease.
   农民不得不淘汰奶牛，以防止疾病传播。
3. 3. The veterinarian performed an operation on the cowto remove the tumor.
   兽医对这头奶牛进行了手术，以切除肿瘤。