7d Fuming sulphuric acid (5) o?e??
12a Billowing white clouds (6)????l?
16d It cooks steaks etc (5,4) Grill something
23aInferior style of writing (8) N???L???
20d In a keen way (6) ???D??
24d Glossy or polished surface (5) ??e??
28a One from SW Arabian republic (6) No letters sorry
I have exhausted Crossword Solver, encarta, google etc.