A first firework is set off at 8 a.m. to alert the runners that the corral gate is (2)_____.10/18A first firework is set off at 8 a.m. to alert the runners that the corral gate is (2)_____.to close closed open openingGiải thíchĐáp án đúng: B The corral gate is closed: Cổng rào đã được đóng