CREATE TABLE "singles_28" (
  "edition" text,
  "round" text,
  "date" text,
  "against" text,
  "surface" text,
  "opponent" text,
  "result" text
);

Question: Who was the opponent for the 2003 davis cup europe/africa group ii?
SQL: SELECT "opponent" FROM "singles_28" WHERE "edition"='2003 davis cup europe/africa group ii';

Question: What is the round when the match was against sergis kyratzis?
SQL: SELECT "round" FROM "singles_28" WHERE "opponent"='sergis kyratzis';