Correct

一发

/ yī fà /
Strokes

Example

As an Adverb

even more; all the more

1
guǒ
如果
chǔ
处理
dàng
不当
  
,
jiù
一发
shōushi
不可收拾
le
  

If not handled properly, the situation would worsen further/become even more hopeless.

As an Adverb

together; along with all others

2
Shū
yǒuguān
有关
liào
资料
一发
shàng
  

I am sending you the book along with the material concerned.