"The" before nouns in plural

[Saneta]

In some book there is written: ,,Remind her about microphones, screns, the projector, pads of papaer, and pencils''. Please explain me when should I use ''the'' before nouns in the plural and where not? Why isn't written in this sentence: the microphones, the screens, the pads of paper and the pencils?

[Milanya]

The definite article is used before singular and plural nouns when the noun is specific or particular. "The" signals that the noun is definite, that it refers to a particular member or members of a group.

[Gian]

Yes, Milanya has given right answer. "The" should be use with singular noun.