food表示食物时,是不可数的;但当用作表示种类时,是可数的。
例如:Most foods that we eat are safe for birds.
我们食用的大多数食物对鸟类都无害。
I think you'd better lay off fatty foods for a while.
我认为你最好暂时别吃高脂食物。
When you buy foods you have certain statutory rights.
在购买食物时,你有一定的法定权利。
Just heat up the food in the microwave.
把食物放在微波炉里热热就行了。
This substance should not come into contact with food.
这种物质切莫与食物接触。