16. I didn't turn
my phone and it rang in the lesson!
A) on
B) in
C) of
D) up​

C)of. нам это задавали. лвбуыввды

A) off

Объяснение:

1. should all library equipment and books be used carefully? how should all library equipment and books be used?

2. shold conversation be kept to a minimum and as quiet as possible? how shouls a conversation be kept?

3. should personal stereos be used in the library? where shouldn't personal stereos be used?

4. should mobile phones be turned off before readres enter the library? where should mobile phones be turned off?

5. is food and drink allowed? why isn't food and drink allowed?

6. should fines for the late return of the books be paid? why should fines be paid?

7. should all books be shown to the librarians before you leave the library? what should be shown to the librarians before you leave the library?

8. should everybody be treated very politely? who should be treated very politely?