Any help with these clues would be appreciated,thanks.
1 across- Leguminous seed making appearance, one ounce (over) ??R????O
12 across- No longer put on show what's faltering in value(7)??V???E
17 across- Taking Germn, men in oral ploughed Cambridge "local"(10)???????I??
28 across- Getting top mark in old German,ready for French(7,three words)??????N
1 down- What's Magog in,struggling,tense and painful?(12)?????T??????
15 down- Plant with edible tuber,worthless? Cunning one cloaks it(9)??R?C???A