cereal意思是麦片粥时，是不可数的。表示谷类植物、谷物时，是可数的。例如，Wheat and rice are cereals.小麦和水稻是谷类植物。

cereal可不可数

意思是谷类食物；麦片粥

breakfast cereals 早餐用的谷类食品

意思是谷类食物时，可数

a bowl of cereal 一碗麦片粥

意思是麦片粥，不可数

cereal例句

1.有变体名词

Cereal or breakfast cereal is a food made from grain.

It is mixed with milk and eaten for breakfast.

I have a bowl of cereal every morning.

2.可数名词

Cereals are plants such as wheat，corn，or rice that produce grain.

...the rich cereal-growing districts of the Paris Basin.