Flu symptoms can be severe, and even fatal, when the illness strikes young children or the elderly.

当病毒攻击幼儿或老人时，流感症状可能很严重甚至是致命的。

youdao

Flu symptoms can be severe, and even fatal, when the illness strikes young children or the elderly.

当病毒攻击幼儿或老人时，流感症状可能很严重甚至是致命的。

youdao