Correct

使力

/ shǐ lì / 
Strokes

Example

As a Verb

exert all one's strength

1
Dàjiā
大家
dōu
都
shǐ
使
lì
力
  
,
rènwu
任务
jiù
就
néng
能
zǎorì
早日
wánchéng
完成
  
。

If everyone works hard, the task can be completed earlier.