根据实际情况填空。 提示:first 第一 second 第二 third 第三 fourth 第四 fifth第五) 1. The canteen is on the _____ floor. 2. The library is on the _____ floor. 3. The computer room is on the _____ floor. 4. The music room is on the _____ floor. 5. Your teacher's office is on the _____ floor.