CREATE TABLE "world_war_i" (
  "estimate" real,
  "name" text,
  "nat" text,
  "ship_type" text,
  "principal_victims" text,
  "date" text
);

Question: What is the nationality of the ship when the principle victims are civilians?
SQL: SELECT "nat" FROM "world_war_i" WHERE "principal_victims"='civilians';

Question: what is the name of the battleship with the battle listed on May 13, 1915?
SQL: SELECT "name" FROM "world_war_i" WHERE "ship_type"='battleship' AND "date"='may 13, 1915';