Correct

导火线

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Strokes

Definition

fuse (for explosives)/(fig.) proximate cause/the last straw

Example

As a Noun

(blasting) fuse

1
Dìngshí
定时
dǎohuǒxiàn
导火线

time fuse

2
Diǎnrán
点燃
dǎohuǒxiàn
导火线

ignite a fuse

As a Noun

immediate cause; small incident that leads to big one

3
Hǎiwān
海湾
zhànzhēng
战争
de
的
dǎohuǒxiàn
导火线
shì
是
shénme
什么
  
?

What is the immediate cause of the Gulf War?