母牛

例句：

1. 1. The farmer milked the cow every morning.
   农民每天早上挤牛奶。
2. 2. The cow was very gentle and didn't mind being handled.
   这头牛非常温顺，不介意被抚摸。
3. 3. Cows are often used for dairy products such as milk and cheese.
   奶牛常用于生产牛奶和奶酪等乳制品。