1, class as a noun means "class, social stratum" and refers to a group with political, social or economic status. Collective noun, which can be used with singular or plural verbs, is mostly in plural form, and can't be counted when it comes to "social class system".

2.class can also be interpreted as "class", which is a countable collective noun. You can use singular or plural, which is often used as singular in American English.

When used in the singular, it means a neutral inanimate whole, which should be referred to by it or which, and the predicate verb is in the singular form; If you use the plural, it means that the living members of this group should be referred to by them or who, and the predicate verb should use the plural.

Extended data class can also represent a specific "course", which is a countable noun. It can also be abstracted as the concept of "class", when the class is uncountable and there is no definite article in front.

Class can also express elegant, noble or admirable manners, appearance, etc. In dress and behavior.

Examples of the use of the class:

This price includes two economy class tickets from Brisbane to Los Angeles.

This price includes two economy class tickets from Brisbane to Los Angeles.

There is little snobbery or class consciousness in the wartime navy.

There were few naval snobs in wartime, and their class consciousness was not strong.

He may not be the strongest in the class.

He may not be the strongest in the class.

You can pay to upgrade to a business class seat.

You can pay to upgrade to business class.

He put forward the connection between class size and test results of 7-year-old children.

He thinks that the test scores of 7-year-old students are related to the class size.

Baidu Encyclopedia-Class