13d) Forbid oil company seizing off-shore US clipper (10) ?A???R???P
18d) Seminar sorted out test cases (8) T??O???L
19a) Knock up article about weak comic (6) A???E?
20d) Naomi, exhausted after a mile, gets gas (7) ??M???A
27a) Focused on recent changes by Germany (7) C??????
28a) Working around head office, not contracted out (2-5) ?? ????E
Many thanks in advance for your help.