火线

huǒ xiàn rù dǎng

火线入党

join the Party at the battlefront

wǒ men qīng shāng bù xià huǒ xiàn

我们轻伤不下火线。

We suffered minor injuries and did not go to the frontline.

shàng huǒ xiàn

上火线

go to the front

shì tú fáng zhǐ píng mín jìn rù huǒ xiàn

试图防止平民进入火线

attempt to prevent civilians from being in the firing line