jǐ / suǐ / huī / zhì / yán / céng / jīng / shì / yì / zhǒng / yán / zhòng / de / ér / tóng / chuán / rǎn / bìng

脊髓灰质炎曾经是一种严重的儿童传染病。

Poliomyelitis used to be a serious infectious disease affecting children.