12. Although all the proceedings of the Communist party conference held in Moscow were not carried live, Soviet audiences have seen a great deal of coverage. (A) all the proceedings of the Communist party conference held in Moscow were not carried live (B) all the Communist party conference’s Moscow proceedings were not carried live (C) all the Communist party conference Moscow proceedings have not been carried alive (D) not all the Communist party conference Moscow proceedings have been carried alive (E) not all the proceedings of the Communist party conference held in Moscow were carried live 时态为什么可以不一致。 key is e
Agree with thornbird. Besides, have you ever seen a TV program being "re-run"? 重播 It is possible to see the conference till now by video tapes. So we use the present perfect tense.