流感季节期间，儿童住院治疗的数量显著上升。

During flu season, there was a noticeable rise in pediatric ___hospitalizations.

他的住院时间因感染需要额外治疗而延长了。

His ___hospitalizations were extended due to an infection that required additional treatment.

冬季期间，流感导致的住院人数显著增加。

During winter, ___hospitalizations due to the flu rise significantly.