Correct

上阵

/ shàngzhèn / 
Strokes

Definition

to go into battle

Example

As a Verb

go into battle

1
Shàngzhèn
上阵
shādí
杀敌

go to the front to fight the enemy

As a Verb

take part in a match; pitch into the work

2
Jīntiān
今天
xiàwǔ
下午
de
的
bǐsài
比赛
nǐ
你
yào
要
shàngzhèn
上阵
  
。

You are going to play in this afternoon's match.

3
Tāmen
他们
yīqǐ
一起
shàngzhèn
上阵
  
,
gōngzuò
工作
hěnkuài
很快
jiù
就
wánchéng
完成
le
了
  
。

They all pitched in and soon finished the job.