LZM第十二章一例题，求解

qqgf

Although [U]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.U]all the proceedings of the Communist party conference held in Moscow were not carried live,Soviet audiences have seen a great deal of coverage.
b.all the communist party conference's Moscow proceedings were not carried live
c.all the communis 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
1)为什么从句部分一定要用一般过去时呢？
2）书上说a,b,c的共同错误是not修饰all,却被放在谓语部分修饰谓语动词，位置不恰当。
那么例句：All his children are not at school表半否定又怎样解释呢》[em18][em27][em24]

thomaszj

例句错了。这个例题是对的，解释也对！