Voicing and devoicing

[apollotiger.livejournal.com]

On the topic of voiced and devoiced consonants, my textbook says that the final letter of a word is always pronounced devoiced, even if voiced (e.g. гараж pronounced as гараш) ... but it also said that if the next word starts in a voiced consonant, the last letter of the previous word will be voiced, even if it's unvoiced (e.g. вас зовут pronounced ваз-зовут).

What about with blends? For example, "без тебя" would be "бес тебя", but would "без твои книги" be "без двои книги"?