Correct

投笔从戎

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Strokes
https://i.cchatty2.com/filters:format(webp)/fit-in/684x0/img/202102/投笔从戎-Chinese-idioms-Cchatty-83ec4227-8603-4871-aabb-87e717ee714b-1612777226.jpg

Collocation

1
投笔从戎的人
2
立志投笔从戎
3
渴望投笔从戎
4
大学生投笔从戎

Definition

投笔丛戒

Literally means:

cast aside the pen and join the army

Actually means:

give up intellectual pursuits for a military career

戎 refers to the army. 从戎 means joining the army. The phrase means an intellectual joins the army.

戎,军队。从戎,参军或当兵。投笔丛戒,指知识分子加人军队。

Example

Used as predicate, object or attributive. (作谓语、宾语、定语)
1
Nàshí
那时
zǔguó
祖国
shòudào
受到
qīnlüè
侵略
  
,
yǒu
有
hěnduō
很多
xuésheng
学生
tóubǐcóngróng
投笔从戎
  
,
bēnfù
奔赴
zhànchǎng
战场
shādí
杀敌
  
。

At that time, the motherland was invaded, there are many students from the pen, rushed to the battlefield to kill the enemy.

2
Xiànzài
现在
yǒu
有
xǔduō
许多
dàxué
大学
bìyèshēng
毕业生
dōu
都
kěwàng
渴望
tóubǐcóngróng
投笔从戎
  
,
qīnzì
亲自
cānjiā
参加
jūnduì
军队
de
的
xiàndàihuà
现代化
jiànshè
建设
  
。

Now there are many college graduates are eager to put pen to paper and personally participate in the modernization of the army.

3
Zhè
这
pī
批
tóubǐcóngróng
投笔从戎
de
的
gōngchéngshī
工程师
zài
在
zhè
这
cháng
场
xìnxīzhàn
信息战
zhōng
中
fāhuī
发挥
le
了
hěn
很
dà
大
de
的
zuòyòng
作用
  
。

The engineers who written the pens played a big role in the information war.