CREATE TABLE "united_states" (
  "c_low" text,
  "c_high" text,
  "i_low" real,
  "i_high" real,
  "category" text
);

Question: How many different C_{high} values are there for the good category?
SQL: SELECT COUNT("c_high") FROM "united_states" WHERE "category"='Good';

Question: What's the C_{high} when the C_{low} value is 250.5?
SQL: SELECT "c_high" FROM "united_states" WHERE "c_low"='250.5';

Question: What's the i_{high} value when C_{low} is 250.5?
SQL: SELECT MIN("i_high") FROM "united_states" WHERE "c_low"='250.5';

Question: What's the C_{low} value when C_{high} is 12.0?
SQL: SELECT "c_low" FROM "united_states" WHERE "c_high"='12.0';

Question: In how many different categories is the value of C_{low} 35.5?
SQL: SELECT COUNT("category") FROM "united_states" WHERE "c_low"='35.5';