Stuck on 3 in top right corner and 3 in bottom left hand corner viz
5 ac Independence Day spurned by radical in review of thriller movie ???R??
6 down Big eater taking to heart the end of die Welt ??E?L
8 down Most of Juno O'Casey composed to hold universal rapture for old poet ??U?S?U?C?
24 across Trample Italian that is after grass P?T???
26 ac Withdrawing a bit of unknown quantity in type of kebab? S?Y??? and
21 down Mountain climbers lifted lid on eminent scientists' group T????