请问all....not...能表部分否定吗

Although all all the proceedings of the communist party conference held in Moscow were not carried live, Soviet audiences have seen a great deal of coverage.

答案选E) not all the proceedings of the Communist party conference held in Moscow were carried live.

觉得以前好像遇到过all....not 表部分否定的情况，为什么这里不选A?

Thanks a lot!!  

When there is both "all..not.." and "not ... all", choose definitely the latter, this is what ETS prefers. (of course you need to look out the rest part of grammar)

marie is right.

我读中学的时候, 老师还强调部分否定要用all ... not, 否则算错. 跟ETS正相反...

I agree with you guys.

Thanks!