Correct

火线

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Strokes

Definition

FireWire (IEEE 1394 data-transfer interface)

Example

As a Noun

battle front/line

1
Huǒxiàn
火线
lìgōng
立功

render meritorious service on the battlefield

2
Huǒxiàn
火线
qiǎngjiù
抢救

frontline first aid

3
Shànghuǒxiàn
上火线

go to the front

As a Noun

live wire; power line