I missed the solution to this crossword last week. I had three left:
12A. First members of CID joined to represent third (10). -E-I-I-C-E. Looks like semicircle but why?
20A. Alternative to Italian music - answer is thus to be written in reverse (5). O-S--
13D. Almost home, take from the mouth a flower (10)
-E-R-S---E. Looks like heartsease ( short hearth, but why sense?)