Am at dead end with last few.
Is 19a A Roman general MECHANIC and if so, why?
I presume 21d It's wonderful up here is HEAVEN
20d A five-year sacrifice 7 N? _ S _ _ _ M
and 16d Island's retaining Sardianian roof styles 8 _ _ _ S _ _ _ S
and 26a They give back segments 9 _ _ _ _ A_ _ _ E
Thanks