foods。food作为食品的统称时为不可数名词，单数形式；指“一种食品时”可数，可以用复数。比如I like all kinds of foods.这里把一个food当成是一种食品，foods指各种食品。
food
英[fu:d] 美[fud] n.
1.[不可数] （人或动物所需的）食物，饮料，（植物所需的）养料；固体食物
eg.They enjoy having Chinese food.
2.[可数] 指某种特定的食品食品 foods
eg.Too many sweet foods may increase your weight.吃太多的甜食可能会是你发胖。
food例句
They are at the end of their food supply.
他们的食物储备已消耗殆尽。
Whether we need more food depends on how many people turn up.
我们是否需要更多的食物，这要视到场人数而定。
Within three days they had exhausted their supply of food.
他们在三天之内就把所有粮食吃光了。
His company offers a flexible packaging service for the food industry.
他的公司为食品工业提供灵活的包装服务。
It seems such a waste to throw good food away.
把好的食物扔掉似乎太浪费了。