milk可数还是不可数名词

　　Calcium is found most abundantly in milk.

　　奶含钙最丰富。

　　I hope you haven't used all the milk.

　　希望你没有把牛奶都用掉了。

　　A skin had formed on the top of the milk.

　　奶上结了一层奶皮。

　　Would you like milk or cream in your coffee?

　　你的咖啡里要牛奶还是奶油？

　　We took the milk run back home.

　　我们回家途中多次停留。