Ant_222 is right, look what Wordnet says:
poster a
horse kept at an inn or post house for use by mail carriers or for rent
to travelers, a sign posted in a public place as an advertisement,
someone who pastes up bills or placards on walls or billboards (so we might as well call a bulletin board user a 'poster')
Ant_222: Thank you for your help with grammar, but I still have some doubts.
8. Because of safety regulations we had to send two drivers instead of one. After a few hundred kilometers it turned out, that although they both have been
(you said that it should be had been, but IMHO using Present Perfect Continuous is more correct, due to the general usage of this tense - actions or events that began in the past and are lasting til now or have recently ended. Notice that they still work as bus drivers) driving buses for many years, neither was used to driving in such heavy traffic.
10. Before the conference I would never have thought that translating a lecture about the history of fashion can
(you said that it ought to be could, but why?) be so difficult. I am afraid that a few listeners could have had doubts about my knowledge of French.
;-)