What is the hometown of the players from alvin high school?
CREATE TABLE "roster" (
  "name" text,
  "num" real,
  "position" text,
  "height" text,
  "weight" real,
  "year" text,
  "home_town" text,
  "high_school" text
);
SELECT "home_town" FROM "roster" WHERE "high_school"='Alvin';