(1) Math - wide bell bottom
(2) Science - less wide bell bottom
(3) English - even less wide bell bottom
(4) Chinese - narrowest bell bottom.(越窄SD值越小哦)
(1) Math - Difficult (low cohort average)
(2) Chinese - Kinda Difficult (kinda low cohort average)
(3) English - Ok (not too low and not too high cohort average)
(4) Science - Easy Peasy (high cohort average)