How to write two libraries in English?

The English of two libraries is two libraries.

Phrase collocation in the library;

Audio library

Audio library.

National Library of China

National Library.

Open access library

Open access library.

Online library

Electronic library.

bookmobile

Mobile/roving library; Mobile book cart.

Bilingual example:

There are nearly one million books in our school library.

There are nearly 1 million books in our school library.

He met his former classmates in the library.

If you go to the library first, save me a seat.

If you go to the library first, please save me a seat.

The library is open from 9 am to 6 pm.

Books borrowed from the library should be returned in full and on time.

All books borrowed from the library should be returned on time.