5a - Impute, assign (7) I have ?S?R???
16a - Degree to which the atmosphere is pollution-free (3,7) I have AIR ?I?L???
18a - Making progress (2,3,5) I have ?N ?H? M?R?E
30a - Under normal circumstances (2,1,4) I have ?S ? R?L?
8d - Puncture (7) I have ??E?P??
Thank You very much for the answers, it seems my 6d is wrong. It's Boot buffer (4,5) I had SHOE SHINE, the SHOE seems okay but I'm left with S?U?H. Any ideas ?