18a. Shah's welcome gift offered first (5) SO--I.
25a. Eg DiMaggio's turn in congress? One must be graduate (5) -T---.
11d. Rush later and place small flowers (11) CAR-EL-ATES.
15d. Radioactive source being clear, settled on alternative finally (9) --ER-LI-E.
21d. Best changing tack around severe sandstorms (7) TE-BA-S.
25d. Cave used by poets? Inside are books in collection (5) -N-RE.
Many thanks in advance folks........am soooooo stuck!!