The protest got out of hand and many police officers tried to hold the protestors ..... behind the barricade.

The protest got out of hand and many police officers tried to hold the protestors ..... behind the barricade. (*) back (*) backing (*) backs (*) backed


This is a companion discussion topic for the original entry at https://english.best/questions/19760,the-protest-got-out-of-hand-and-many-police-officers-tried-to-hold-the-protestors-___-behind-the-barricade/